Question

How many quarts of a 50% solution of acid must be added to 20 quarts of a 20% solution of acid to obtain a mixture containing a 40% solution of acid? Answer:

Answer 1

Answer: 40 quarts

Explanation:

let x = amount of the 50% solution

A typical mixture equation using the decimal equivalent to

.50x + .20(20) = .40(x+20)

.50x + 4 = .40x + 8

.50x - .40x = 8 - 4

.10x = 4

x = 4/.1

x = 40 qts of 50% solution

Hence 40 quarts of 50% solution must be added.

Answer 2

40 quarts.

Explanation:

Let x =quarts of the 50% solution

so, according to the question

the typical mixture equivalent equation will be like this

`.50x + .20(20) = .40(x+20)\\.50x + 4 = .40x + 8\\.50x - .40x = 8 - 4\\.10x = 4\\x = 4/.10 \\x = 40`

so the answer will be 40 quarts of 50% solution should be added.