Amixture contains five quarts of acid and water and is forty percent acid. if the mixture is to be weakened to thirty percent acid, how much water must be added?

  of water must be added.

Step-by-step explanation:

Given : The total quantity of mixture = 5 quarts

The percentage of acid= 0.40

Then, total liters of acid is given by :-

The amount of water in the given mixture :

The percentage of acid in in weakened mixture = 0.30

Then , the percentage of water in weakened mixture = 0.70

Let 'x' amount of water is added to mixture.

Then According to the question ,we have the following equation :-

Hence, of water must be added.

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240

answer: i wpould go with c

step-by-step explanation: