A vessel contained a solution of acid and water, in which water was 64%. Four litres of the solution was taken out of the vessel and the same quantity of water was added. If the resulting solution contains 30% acid, the quantity (in litres) of the water in the solution, at the beginning in the vessel, was:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 15.36
Let the initial solution of the solution be 100a.
Quantity of Water = 64a.
Quantity of Acid = 36a.
According to the question,
Quantity of water in 4 litre solution = 4 × 64/100 = 2.56 litres
Quantity of water in the final solution = 64a - 2.56 + 4 = (64a + 1.44)
Quantity of Acid in the mixture after replacement = (36a - 1.44).
According to the question,
(64a + 1.44)/(36a - 1.44) = 7/3
On solving this equation we get,
a = 0.24
Quantity of water in the beginning = 64a = 64 × 0.24 = 15.36 litres.