Answer:
66 gallons
Step-by-step explanation:
Given that initially 160 gallons of a solution containing 12% salt.
So, the initial amount of salt = 12% of 160 = 12/100 x 160 = 19.2 gallons.
Let x gallons of water get evaporated so that the remaining solution contains 20% salt.
The remaining amount of solution = 160-x gallons.
As the initial amount of salt is still in the solution which is equal to 20% of the remaining solution, so
19.2 = 20% of (160-x)
![\Rightarrow 19.2 = \frac {20}{100}\times (160-x) \\\\\Rightarrow 19.2 = \frac {1}{5}\times (160-x) \\\\\Rightarrow 19.2 \times 5= 160-x \\\\\Rightarrow 96= 160-x \\\\\Rightarrow x= 160-96 \\\\](https://tex.z-dn.net/?f=%5CRightarrow%2019.2%20%3D%20%5Cfrac%20%7B20%7D%7B100%7D%5Ctimes%20%28160-x%29%20%5C%5C%5C%5C%5CRightarrow%2019.2%20%3D%20%5Cfrac%20%7B1%7D%7B5%7D%5Ctimes%20%28160-x%29%20%5C%5C%5C%5C%5CRightarrow%2019.2%20%5Ctimes%205%3D%20160-x%20%5C%5C%5C%5C%5CRightarrow%2096%3D%20160-x%20%5C%5C%5C%5C%5CRightarrow%20x%3D%20160-96%20%5C%5C%5C%5C)
gallons
Hence, 66 gallons of water must be evaporated to get a 20% salt solution.
Answer:
60x$70=$4100
Step-by-step explanation:
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9514 1404 393
Answer:
256 feet
Step-by-step explanation:
The vertex of the quadratic ax^2 +bx +c is found at x=-b/(2a). This means the time at which the rocket reaches it maximum height is ...
t = -128/(2(-16)) = 4 . . . . seconds
Evaluating h at t=4 gives the maximum height:
h = -16(4^2) +128(4) = -256 +512 = 256
The maximum height of the rocket is 256 feet.
_____
If you can read this value from "the graph at the left," you can save yourself some computation.
Answer:
65; 117; 143.
Step-by-step explanation:
1. if the ratio is 5/9/11 and the perimeter is a+b+c=325, then it is possible to write (for the perimeter):
5x+9x+11x=325;
2. to calculate the value of 'x':
x=13;
3. the required sides are:
5x=65; 9x=117; 11x=143.