The radius of a circular ring is 4 feet. What is the circumference?
Answer: D.) 25.12 feet
Step-by-step explanation:
We apply the formula to calculate the circumference knowing the radius. We consider π = 3.14
C = 2 x π x Radius = 2 x 3.14 x 4 feet = 25.12 feet
Answer : D.) 25.12 feet
[tex]\textit{\textbf{Spymore}}[/tex]
The circumference of the circle is 25.12 feet.
The radius of a circular ring is 4 feet.
We have to determine the circumference
We apply the formula to calculate the circumference by knowing the radius.
We consider π = 3.14
What is the formula for the circumference of the circle?
C = 2 x π x Radius
use the given values in the above formula so we get,
C= 2 x 3.14 x 4 feet
C= 25.12 feet
Therefore option D is correct.
The circumference of the circle is 25.12 feet.
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The function y = –16t2 + 486 models the height y in feet of a stone t seconds after it is dropped from the edge of a vertical cliff. How long will it take the stone to hit the ground? Round to the nearest hundredth of a second.
Question 7 options:
0.25 seconds
5.51 seconds
11.02 seconds
7.79 seconds
5.51 seconds
Step-by-step explanation:y = 0 when the stone hits the ground. At that point, t can be found from ...
... 0 = -16t^2 +486
... 0 = t^2 -30.375 . . . . divide by -16
... 30.375 = t^2 . . . . . . add the opposite of the constant
Take the square root to get ...
... √30.375 = t ≈ 5.51 . . . . seconds
Write the expression 2a+b in the form of a fraction with a denominator of: b
[tex]2a+b=\dfrac{2ab}{b}+\dfrac{bb}{b}=\dfrac{2ab}{b}+\dfrac{b^2}{b}=\boxed{\dfrac{2ab+b^2}{b}}[/tex]
On the main street, the tourists walked for s km with a speed of v km/hour. On the side road, the tourists walked twice the distance that they covered on the main street. How much time t (in hours) did the tourists spend if it is known that on the side road they walked with a speed that was 2 km/hour less than their speed on the main road? Find t when s=10, v=6.
Answer:
6 2/3 hours
Step-by-step explanation:
We assume the time of interest is the total time spent on the main road and side road.
In each case, ...
... time = distance/speed
On the main road, ...
... tmain = s/v
On the side road, ...
... tside = (2s)/(v -2)
Then the total time spent is ...
... ttotal = tmain + tside
... = s/v + (2s)/(v -2)
For s=10 and v=6, this is ...
... ttotal = 10/6 + 2·10/(6 -2) = 5/3 + 20/4 = 5/3 + 5 . . . . hours
... ttotal = 6 2/3 hours
Answer:
6 hr 40 min
Step-by-step explanation:
Eric is 6 1/6 feet tall and his brother is 5 3/4 feet tall. Eric is how many feet taller than his brother?
A. 1/5 feet
B. 5/12 feet
C. 7/12 feet
D. 3/4 feet
Answer:
B. 5/12 feet
Step-by-step explanation:
We know that Eric is [tex]6\frac{1}{6}[/tex] feet tall while his brother is [tex]5\frac{3}{4}[/tex] feet tall. We are supposed to find out how many feet is Eric taller than his brother.
So basically we have to find the difference between the height of the two brothers.
First, let's just change the mixed numbers to improper fractions:
[tex]6\frac{1}{6}[/tex] = [tex]\frac{37}{6}[/tex]
[tex]5\frac{3}{4}[/tex]= [tex]\frac{23}{4}[/tex]
Now taking their difference:
[tex]=\frac{37}{6} -\frac{23}{4}\\\\=\frac{148-138}{24}\\\\=\frac{10}{24}\\\\=\frac{5}{12}[/tex]
Therefore, Eric is 5/12 feet taller than his brother.
please help me asap!
Answer:
2968.30 cm cube.
Step-by-step explanation:
Given is a cone and top of it is a hemisphere of radius 9 cm.
Cone has height as 17 and radius same 9 cm.
We have to find the volume of the compound shape
We find that the volume would be the sum of that of hemisphere of radius 9 cm and cone of height 17, and radius 9 cm.
Volume of compound shape = volume of cone+Volume of hemisphere
= [tex]\frac{1}{3} \pi r^{2} h+\frac{2}{3} \pi r^{3}[/tex]
substitute for h and r in the equation
Required volume =
[tex][tex]\frac{1}{3}\pi r^{2} (h+2r) = \frac{1}{3}\pi 9^{2} (17+2(9))\\= 1441.99+1526.31\\=2968.30[/tex][/tex]
So answer is 2968.30 cm cube.
=
Select Linear or Nonlinear for each function. Function Linear Nonlinear y=5x+1 y=23 y=1−2x2
The correct classification for each function is as follows:
1. [tex]\( y = 5x + 1 \)[/tex] - Linear
2. [tex]\( y = 23 \)[/tex] - Linear
3. [tex]\( y = 1 - 2x^2 \)[/tex]- Nonlinear
A linear function is one that can be written in the form [tex]\( y = mx + b \)[/tex], where [tex]\( m \)[/tex] and [tex]\( b \)[/tex] are constants, and [tex]\( x \)[/tex] is the independent variable. The graph of a linear function is a straight line.
1. For the function [tex]\( y = 5x + 1 \)[/tex], we can see that it is already in the form of a linear equation with [tex]\( m = 5 \)[/tex] and [tex]\( b = 1 \)[/tex]. Therefore, this function is linear.
2. The function [tex]\( y = 23 \)[/tex] is a constant function. Although it does not have an [tex]\( x \)[/tex] term, it can still be considered linear because it can be written as [tex]\( y = 0x + 23 \)[/tex], where the slope [tex]\( m = 0 \)[/tex] and the y-intercept [tex]\( b = 23 \)[/tex]. The graph of this function is a horizontal line, which is a special case of a linear function.
3. The function [tex]\( y = 1 - 2x^2 \)[/tex] contains an [tex]\( x^2 \)[/tex] term, which makes it a quadratic function. Quadratic functions are nonlinear because their graphs are parabolas, not straight lines. The presence of the [tex]\( x^2 \)[/tex] term means that the rate of change of [tex]\( y \)[/tex] with respect to [tex]\( x \)[/tex] is not constant, which is a key characteristic of nonlinear functions. Therefore, this function is nonlinear.
What type of function is this ? 15 points
Answer:
quadratic polynomialminimum at (1, -9)decreasing on (-1, 1)Step-by-step explanation:
1. First differences in the y-values are ...
... -5-0 = -5; -8-(-5) = -3; -9-(-8) = -1; -8-(-9) = 1; -5-(-8) = 3; 0-(-5) = 5
Second differences are ...
... -3-(-5) = 2; -1-(-3) = 2; 1-(-1) = 2; 3-1 = 2; 5-3 = 2
These 2nd differences are constant, so the points can be described by a 2nd-degree polynomial.
2. Values on the graph range from 0 to a low of -9 and back up to 0. There is a minimum at (1, -9).
3. The value at x=-1 is -5; at x=1, it is -9, which is less than -5. The function is decreasing on the interval -1 to 1.
find an equation with vertical asymptotes 1 and 4 and horizontal asymptote 1 please help
Answer:
y = 1 + 1/((x -1)(x -4))
Step-by-step explanation:
To get vertical asymptotes at 1 and 4, you need factors (x -1) and (x -4) in the denominator. As x approaches 1 or 4, one of these will approach zero, and the function value will approach infinity.
To get a horizontal asymptote of 1, the function must approach the value 1 when the value of x gets large (positive or negative). This can generally be accomplished by simply adding 1 to a fraction that approaches zero when x is large.
Here, we make the fraction be the one that gives the vertical asymptotes, and we simply add 1 to it.
... y = 1 + 1/((x -1)(x -4))
If you like, this can be "simplified" to ...
... y = (x² -5x +5)/(x² -5x +4)
_____
In this rational expression form, please note that the numerator and denominator have the same degree. That will be the case when there is a horizontal asymptote. (When a slant asymptote, the numerator degree is 1 higher than the denominator.) The ratio of the coefficients of the highest degree terms is the horizontal asymptote value (or the slope of a slant asymptote).
What can you say about the y-values of the two functions f(x)=-5^x +2 and g(x)=-5x^2+2?
A) f(x) and g(x) have equivalent maximum values
b) The maximum y-value of f(x) approaches 2
c) g(x) has the largest possible y-value
d) f(x) has the largest possible y-value
Its multiple choice
Answer:
B) The maximum y-value of f(x) approaches 2
C) g(x) has the largest possible y-value
Step-by-step explanation:
f(x)=-5^x+2
f(x) is an exponential function.
Lim x→∞ f(x) = Lim x→∞ (-5^x+2) = -5^(∞)+2 = -∞+2→ Lim x→∞ f(x) = -∞
Lim x→ -∞ f(x) = Lim x→ -∞ (-5^x+2) = -5^(-∞)+2 = -1/5^∞+2 = -1/∞+2 = 0+2→
Lim x→ -∞ f(x) = 2
Then the maximun y-value of f(x) approaches 2
g(x)=-5x^2+2
g(x) is a quadratic function. The graph is a parabola
g(x)=ax^2+bx+c
a=-5<0, the parabola opens downward and has a maximum value at
x=-b/(2a)
b=0
c=2
x=-0/2(-5)
x=0/10
x=0
The maximum value is at x=0:
g(0)=-5(0)^2+2=-5(0)+2=0+2→g(0)=2
The maximum value of g(x) is 2
Evaluate the expression 3a+2b/2 when a = -3 and =-4
The solution of the expression 3a+2b/2 is -13 when a = -3 and b = -4
What is the expression?Expressions are defined as mathematical statements that have a minimum of two terms containing variables or numbers.
What are Arithmetic operations?Arithmetic operations can also be specified by subtracting, dividing, and multiplying built-in functions.
The operator that performs the arithmetic operation is called the arithmetic operator.
Operators which let do a basic mathematical calculation
+ Addition operation: Adds values on either side of the operator.
For example 4 + 2 = 6
- Subtraction operation: Subtracts the right-hand operand from the left-hand operand.
for example 4 -2 = 2
* Multiplication operation: Multiplies values on either side of the operator
For example 4*2 = 8
Given the expression as :
⇒ 3a + 2b/2
when a = -3 and b = -4
Substitute the values of a and b
⇒ 3 × (-3) + 2 × (-4/2)
⇒ -9 - 4
⇒ -13
Hence, the solution of the expression 3a+2b/2 is -13 when a = -3 and b = -4
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The angle measure of a triangle are 2x + 5 degrees, 6x - 5 degrees, and 7x degrees. What is each angle measure
DAY 15: The measures of the angles in a certain triangle are in the ratio 1: 5: 6. Find the measure of the smallest angle.
x +5x +6x=180
12x =180
x=15º
DAY 16: In triangle ABC, the measure of angle A = 7x - 32, the measure of angle B = 3x + 4, and the exterior angle at C has measure 12 (x - 5). Find the value of x.
exterior angle = sum of two remote (other) interiors
7x -32 +3x+4 =12(x-5)
10x -28 =12x -60
32-2x
x=16
DAY 17: Find the slope of the line perpendicular to the line through the points (21, 11) and (-4, -12).
11 - -12 / 21 - -4 =23/25
slope of perpendicular line is negative reciprocal =
-25/23 ( no 17!)
DAY 18: In a certain triangle, the largest angle is 6 times the smallest. The third angle is 18 less than 4 times the smallest. What is the measure of the smallest angle?
x= smallest
6x =largest
third angle =4x-18
x+6x +4x-18 =180
11x =198
x=18º
For what values of x does the following hold true:
a. (5x+3)^2=5(x+3)
b. (3x+10)^2=3(x+10)
c. (3x−8)^2=3x^2−8x
a. x ∈ {-1.2, 0.2}
b. x ∈ {-4 2/3, -1 2/3}
c. x ∈ {2 2/3, 4}
Step-by-step explanation:For this sort of exercise, I find a graphing calculator to be very handy. While the one shown in the attachment (Desmos) can solve the equation as written, I find it convenient to recast the equation to the form f(x) = 0. The calculator finds the values of zero crossings very nicely. Some, like my TI-84, will show the value to 8 or 10 significant digits. Here, 4 digits is sufficient to determine the exact solution.
_____
If you want to work these by hand, you rewrite them to standard form, then use factoring, completing the square, or the quadratic formula to solve them.
a. 25x² +30x +9 -5x -15 = 0 . . . . subtract the right side
... 25x² +25x -6 = 0 . . . . . . . . . . . collect terms
... (5x+6)(5x-1) = 0 . . . . . . . . . . . . . factor (the graphing calc helps here)
... x = -6/5, 1/5
b. 9x² +60x +100 -3x -30 = 0 . . . . subtract the right side
... 9x² +57x +70 = 0 . . . . . . . . . . . . collect terms
... (3x +14)(3x +5) = 0 . . . . . . . . . . . factor
... x = -14/3, -5/3
c. 9x² -48x +64 -3x² +8x = 0 . . . . . subtract the right side
... 6x² -40x +64 = 0 . . . . . . . . . . . . collect terms
... 3x² -20x +32 = 0 . . . . . . . . . . . . factor out 2
... (3x -8)(x -4) = 0 . . . . . . . . . . . . . . factor
... x = 8/3, 4
A local garden club had 14 members with a mean age of 34. Then two new members joined. One was 24 years old, and the other was 36 years old. How did the mean age change after they joined? The mean age increased. The mean age decreased. It isn't possible to determine how the mean would change. The mean age stayed the same.
The mean age decreased.
Step-by-step explanation:I find it convenient to look at the additions with respect to the current mean age.
The current total age is 14×34. We have added members with ages (34 -10) and (34 +2), so the new total age is ...
... (34×14) + (34 -10) + (34 +2) = (16×34) - 8
Dividing this total by 16 will give the new mean age. (We already know it is less than 34.)
... ((16×34) -8)/16 = 34 - 1/2 = 33 1/2 . . . new mean age; a decrease
Which of the following is defined by distinct lines which intersect at right angles and at exactly one point
How many no real complex roots does the polynomial f (x) = x^4 - x^2- 12 have?
A. 0
B. 1
C. 2
D. 3
E. 4
f(x) factors as ...
... f(x) = (x² -4)(x² +3) = (x -2)(x +2)(x² +3)
The real roots are x = ±2.
The complex roots are x = ±i√3.
___
We don't know what "no real complex roots" means. We suspect your answer may be C. 2.
In the 9th and 10th grades at Jefferson High School, there are 236 students. Of thoes students, 121 are in 9th grade, Of the 214 students who are right- handed, 103 of them are in 10th grade.
Total -
Right-handed: 214! Left-handed: 22!
Total of students: 236 students
I hope this helped! :D
Step-by-step explanation:
9th Grade: Right Handed: 111! Left Handed: 10!
10 Grade: Right Handed: 103! Left Handed: 22!
Add left handed for both grades. Add right handed for both grades. And add total numbers.
I hope this helped :D
There are 121 students in 9th grade and 115 students in 10th grade at Jefferson High School.
Explanation:This question involves counting and analyzing data about grade levels and handedness of students at Jefferson High School. To answer the question, we need to use the given information:
- There are 236 students in 9th and 10th grades combined.
- Out of these, 121 students are in 9th grade.
- Among the 214 right-handed students, 103 are in 10th grade.
We can use these numbers to find out how many students are in each grade level.
Let's denote the number of 9th-grade students as 'x' and 10th-grade students as 'y'.
From the given information:
x + y = 236 (total number of students)
x = 121 (number of 9th-grade students)
y = 103 (number of 10th-grade students)
To find the value of 'y', we can substitute the given value of 'x' into the first equation:
121 + y = 236
y = 236 - 121
y = 115
Therefore, there are 121 students in 9th grade and 115 students in 10th grade.
Can someone please answer this for me.
Answer:
See picture
Step-by-step explanation:
The rule is ...
[tex]x^{m/n}=\sqrt[n]{x^m}[/tex]
The index of the surd becomes the denominator of the exponents inside.
Answer:
x^(5/3)*y^(1/3)
Step-by-step explanation:
note (a*b)^c = a^c*b^c
the given expression can be rewritten as (x^5*y)^1/3
=x^(5/3)*y^(1/3)
ans is the 2nd choice
A silicon chip is 14 nanometers thick. A nanometer is equal to 0.000000001 meter. Express the thickness of the chip using scientific notation.
Answer:
1.4 × 10^-8
Step-by-step explanation:
The chip is 14 nanometers
14 * .000000001
.000000014
Move the decimal 8 places to the right, because we need 1 number in front of the decimal for scientific notation. The exponent will be -8 because we moved it 8 places to the right
1.4 × 10^-8
The thickness of the silicon chip in scientific notation is 1.4 x 10^-8 m.
Explanation:To express the thickness of the silicon chip in scientific notation, we need to convert the given thickness of 14 nanometers to meters.
Since 1 nanometer (nm) is equal to 0.000000001 meters, we can convert 14 nanometers to meters by multiplying it by the conversion factor:
14 nm x 0.000000001 m/nm = 0.000000014 m
Now, we can express the thickness of the chip in scientific notation:
0.000000014 m = 1.4 x 10-8 m
answer quickly please il give brainliest
Answer:
Second Option is the correct answer 3/2
Step-by-step explanation:
Tangent of an angle in a triangle is given by Perpendicular of that triangle / Base of that triangle , with resoect to angle in consideration.
Tangent Ratio for angle B = Perpendicular / Base
Tangent Ratio for angle B = AC / BC
Tangent Ratio for angle B = 3/2
Hope it helps.
Thank you.
Which equation has the same solution as this equation? x^2-16x+12=0
Another equation that shares the same solutions as x²-16x+12=0 is 2x² - 32x + 24 = 0. This equation is the initial equation multiplied by 2 and thus would produce the same solutions when the quadratic formula is applied.
Explanation:The equation given is a quadratic equation, which is in the form ax²+bx+c = 0. The solutions of a quadratic equation are given by the formula: -b ± √b² - 4ac / 2a. This formula can be used to find the solutions of any other quadratic equation. For the given equation, x²-16x+12=0, the values of a, b, and c are 1, -16, and 12 respectively. So, another equation with the same solutions could be 2x² - 32x + 24 = 0. This equation has the same solutions because it's simply the initial equation multiplied by 2, so this doesn't change the results of the quadratic formula.
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please help i will give brainliest
For this case, we have that by definition:
Let "x" be an angle of any vertex of a right triangle.
[tex]tangent (x) = \frac {Cathet \ opposite} {Cathet \ adjacent}[/tex]
So, if we want to find the tangent of angle A:
[tex]tangent (A) = \frac {6} {8}[/tex]
Thus, the tangent of angle "A" is [tex]\frac {6} {8}[/tex]
Answer:
[tex]\frac {6} {8}[/tex]
Option b
Just number 9 not the other one please help
Answer:
I do believe the answer is C
Step-by-step explanation:
.004 / .0004 =
Answer:
c 10
Step-by-step explanation:
If we want to know how much bigger object A is than object B is we take object A and divide it by object B
object A 4 * 10^-3
----------- = -------------
Object B 4 * 10 ^-4
When dividing exponents with the same base
We can subtract them. The numbers out front get divided
4/4 * 10 ^ (-3- -4)
1 * 10 ^(-3+4)
1 * 10 ^1
10
Please help me with this one
The variables y and x have a proportional relationship, and y = 7 when x = 2.
What is the value of y when x = 5?
The variables y and x have a proportional relationship, and y = 7 when x = 2.
What is the value of x when y = 21?
Which equation represents a proportional relationship?
y=−x
y=−5(x+1)
y = 5x + 1
y=15x
Answer:
y= 35/2 when x=5
x=6 when y =21
Proportinal relatiionships: y=−x , y=15x
Step-by-step explanation:
The formula for direct variation is
y= kx
If y=7 and x=2, we can solve for k
7 =k*2
Divide by 2
7/2 =k
y =7/2 x
Now if x=5
y =7/2 * 5
y =35/2
Now if y=21
21 =7/2 * x
Multiply by 2/7
21 * 2/7 = 7/2 * 2/7 x
6 =x
Which equation represents a proportional relationship?
y=−x
YES k = -1 Some people debate about having a negative constant, but everything I have read and taught says you can have a negative constant.
y=−5(x+1)
This does not go through the origin so no
if x=0 y = -5
y = 5x + 1
if x = 0 y =1 so no
y=15x
YES k = 15
Answer:
17.5
i just did it on my quiz and it was wrong(the other guy is wrong)
Parker and Company pays Selma Stokes on a variable commission scale. In a month when Selma had net sales of $155,000, what was her Gross Pay based on the following scale?
Net Sales Commission Rate
Up to $40,000 5%
Excess of $40,000 to $75,000 5.5%
Excess of $75,000 to $100,000 6%
More than $100,000 7%
Answer:
$9275
Step-by-step explanation:
Selma earns 5% on the first $40,000, which is $2000.
She earns 5.5% on the next $35,000, which is $1925.
She earns 6% on the next $25,000, which is $1500.
And she earns 7% on the last $55,000 (the amount over 100,000), which is $3850.
Altogether, Selma's commission is ...
... $2000 +1925 +1500 +3850 = $9275.
_____
Comment on the sliding scale
Each of the segments of this sliding scale could be rewritten to simplify its computation. For example, for amounts above $100,000, the formula could be either of ...
7% of the amount over $22,5007% of sales, less $1575.Which relation is displayed in this table? x y
5 5
A. {(5, 5), (6, −6), (8, 7), (−9, 9)} 8 7
6 -6
-9 9
B. {(5, 5), (−6, 6), (7, 8), (9, −9)}
C. {(−5, 5), (−6, 6), (−8, 7), (−9, 9)}
D. {(5, −5), (6, −6), (8, −7), (9, −9)}
A. {(5, 5), (6, −6), (8, 7), (−9, 9)}
Step-by-step explanation:Compare the table contents to the ordered pairs in each relation. The first pair of table values, (5, 5) matches relations A and B, but not C or D.
The second pair of table values (8, 7), matches relation A, but not B. Since all pairs of table values show up in relation A, and we have rejected relations B, C, and D as inappropriate choices, the answer is A.
Which transformation maps the strip pattern onto itself pdpd
half-turn
Step-by-step explanation:There is a point of rotational symmetry at the center of the pattern. Thus, turning it 180° (a half-turn) will map it to itself.
_____
Comment on other choices
Any sort of reflection will change it to bqbqbqbqbq. Translation puts its somewhere else, not on top of itself.
Answer:
A half turn reversal of direction (as in a staircase) either by one 180-degree turn or two right-angle turns
Step-by-step explanation:
Hope this helps :) -Mark Brainiest Please :)
In the figure below, TRS = RTU and SR = UT. Which of the following triangle congruence criteria proves that TRS = RTU
HELLP MMMEEE PLZ
Answer:
B. side-angle-side
Step-by-step explanation:
You are given that side SR matches its counterpart; angle SRT matches its counterpart; and you know side ST matches its counterpart, because they are the same segment.
Hence, you have two matching sides and the angle between them. This set of side-angle-side lets you invoke the theorem that matches that name.
I need help on this. The portrait studio can buy photographs on canvas. The small canvas photograph print is $20 and the large canvas photograph is $45. The studio wants to sell twice as many small prints as large prints. The studio also has to make at least $510 total to cover the costs of printing. How many of each type does the studio need to sell?
Numerical Reasoning
Consider a set of prints that consists of 2 small prints and one large print (that is, twice as many small prints as large). The value of that set will be ...
... 2×$20 +45 = $85
To have revenue of at least $510, the studio must sell ...
... $510/$85 = 6
sets of prints. That is, the studio needs to sell at least 6 large prints and 12 small ones.
_____
With an equation
Let x represent the number of large prints the studio needs to sell. Then 2x will represent the number of small prints. Total sales will be ...
... 20·2x +45·x ≥ 510
... 85x ≥ 510
... x ≥ 510/85
... x ≥ 6
The studio needs to sell at least 6 large prints and 12 small prints.
How much water must be evaporated from 20 gallons of a 10% salt solution in order to obtain a 20% salt solution?
Answer:
8 gallons have to be evaporated to have a 20% salt solution.
hope this helped :)
Step-by-step explanation:
.10*20=2 gallons of salt.
That leaves 18 gallons of water.
.2x=2
x=2/.2
x=10 gallons after evaporation.
18-10=8
To obtain a 20% salt solution from a 10% salt solution, 20 gallons of water must be evaporated.
Explanation:To obtain a 20% salt solution from a 10% salt solution, the amount of water that needs to be evaporated can be calculated using a proportion. First, convert the percentages to decimals by dividing them by 100. Let x be the amount of water to be evaporated. The amount of salt in the initial solution is 10% of 20 gallons, or 0.10 * 20 = 2 gallons. The resulting solution will have 20% salt in a total volume of 20 - x gallons. Set up a proportion:
(2 gallons)/(20 gallons) = (0.20 * (20 - x) gallons)/(20 - x gallons)
Cross multiply and solve for x:
2(20 - x) = 0.20(20 - x)
Now solve the equation:
40 - 2x = 4 - 0.20x
2x - 0.20x = 40 - 4
1.8x = 36
x = 36/1.8
x = 20
Therefore, 20 gallons of water must be evaporated from the initial 20-gallon solution to obtain a 20% salt solution.
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