Question

A can contains a mixture of two liquids a and b in the ratio 7 : 5. When 9 litres of mixture are drawn off and the can is filled with b, the ratio of a and b becomes 7 : 9. How many litres of liquid a was contained by the can initially

Answer 1

Step-by-step explanation:

Suppose the can initially contains 7x and 5x of mixtures A and B respectively.

Quantity of A in mixture left = 7x - 7 x 9 litres = 7x - 21 litres.

12 4

Quantity of B in mixture left = 5x - 5 x 9 litres = 5x - 15 litres.

12 4

7x - 21

4

= 7

5x - 15 + 9

4

9

28x - 21 = 7

20x + 21 9

252x - 189 = 140x + 147

112x = 336

x = 3.

So, the can contained 21 litres of A.