40 liters of a mixture contains acid and water in the ratio 7:3. How much acid must be added to make the ratio 4:1?
Show answer & explanation
Correct answer: D
Explanation
Given:
Total mixture = 40 liters
Acid : Water = 7 : 3
Total parts = 7 + 3
Acid = (7/10) × 40 = 28
Water = (3/10) × 40 = 12
Let the amount of acid added = x
New ratio = 4 : 1
(28 + x) / 12 = 4 / 1
28 + x = 48
x = 20
Acid added = 20 liters