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.

207/8 is the right

the answer is y < -3 or   y > 3

-3y > 7 + 2

-3 y > 9

y < -3