Multiple choice

In a tank, the ratio of two liquids A and B is 4 : 1. When 10 litres of the mixture is replaced by 10 litres of liquid B, the new ratio of liquid A and B in the tank becomes 2 : 3. How much quantity of liquid A was contained in the tank?

  1. 10 litres

  2. 12 litres

  3. 15 litres

  4. 16 litres

  5. 17 litres
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let the initial amount of A be 4x and B be x. Total = 5x. When 10L is removed, 8L of A and 2L of B are removed. Remaining: A = 4x - 8, B = x - 2 + 10 = x + 8. Ratio (4x-8)/(x+8) = 2/3. 12x - 24 = 2x + 16, so 10x = 40, x = 4. Initial A = 4*4 = 16 litres.

AI explanation

Let the initial volume of the mixture be 5x, so liquid A is 4x and liquid B is x. When 10 litres is replaced by liquid B, 8 litres of A and 2 litres of B are removed, leaving 4x - 8 of A and x - 2 + 10 of B. The new ratio is (4x - 8) to (x + 8), which equals 2 to 3. Solving 3(4x - 8) = 2(x + 8) gives 12x - 24 = 2x + 16, so x equals 4. The initial quantity of liquid A is 4x, which is 16 litres.

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