In a 60 liter solution of acid and water, the ratio of acid and water is 3 : 7. How much (in liter) acid is to be mixed in the solution so that the ratio of acid and water in the resulting solution is 1 : 2?
Answer & explanation
Correct answer: option 3
Acid : Water.
3 : 7
⇒ (3 + 7)units = 60 L
⇒ 10 units = 60L
⇒ 1 unit = 6 L
⇒ Acid = 3 x 6 = 18 L
⇒ Water = 7 x 6 = 42 L
⇒ Amount of acid to be added to make ratio 1 : 2
⇒ 2 units = 42,
⇒ 1 unit = 21,
⇒ 21 - 18 = 3 L
⇒ Therefore 3 L acid to be added to make ratio of acid and water 1 : 2.