140 liters of a solution is formed by mixing two solutions A and B. The concentrations of milk in A and B are 40% and 75%, respectively. If the resultant solution has a milk concentration of 52%, then what is the quantity of A that is there in the resultant solution?

92 litres

Let's assume that x liters of solution A is mixed with with (140 - x)liters of solution B to get the resultant solution of 140 liters with a milk concentration of 52%.

⇒ The milk quantity in solution A = 40% of x,

⇒ The milk quantity in solution B = 75% of (140 - x)

⇒ The total milk quantity in the resultant solution = 52% of 140.

⇒ We can't write the following equation based on the above information:

⇒ 0.4x + 0.75(140 - x) = 72.8

⇒ -0.35x = 32.2

⇒ x = 92.

Therefore, answer is 92.