Jar A has 60 litres of mixture of milk and water in the respective ratio of 2 : 1. Jar B which had 40 litres of mixture of milk and water was emptied into jar A, as a result in jar A, the respective ratio of milk and water became 13 : 7. What was the quantity of water in jar B?

Jar A has 60 litres of mixture of milk and water in the respective ratio of 2 : 1

=> Quantity of milk in Jar A = $$\frac{2}{3} \times 60 = 40$$ litres

Quantity of water in Jar A = $$60 - 40 = 20$$ itres

Let quantity of water in Jar B = $$x$$ litres

=> Quantity of milk in Jar B = $$(40 - x)$$ litres

Acc. to ques, => $$\frac{40 + (40 - x)}{20 + x} = \frac{13}{7}$$

=> $$560 - 7x = 260 + 13x$$

=> $$13x + 7x = 560 - 260$$

=> $$20x = 300$$

=> $$x = \frac{300}{20} = 15$$ litres