Question

A and B are solutions of acid and water. The ratios of water and acid in A and B are 4 : 5 and 1 : 2 respectively. If x liters of A is mixed with y liters of B, then the ratio of water and acid in the mixture becomes 8 : 13 What is x : y?

• A. 5 : 6
• B. 3 : 4
• C. 2 : 3
• D. 2 : 5

Answer 1

Answer:

B. 3 : 4

Given: Ratio of water and acid in A = 4 ∶ 5 Ratio of water and acid in B = 1 ∶ 2 Calculations: Taking the ratio of water and acid in A and B in the equal unit, Ratio of water and acid in A = 4 ∶ 5 Ratio of water and acid in B = 3 ∶ 6 Ratio of water and acid in the mixture = (4x + 3y)/(5x + 6y) ⇒ (4x + 3y)/(5x + 6y) = 8/13 ⇒ 52x + 39y = 40x + 48y ⇒ 12x = 9y ⇒ x/y = 9/12 ⇒ x/y = 3/4 ∴ The ratio of x and y is 3 ∶ 4