Question

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

Answer 1

Answer:

21

Step-by-step explanation:

Let the can initially contain 7x litre and 5x litre of mixture A and B respectively. Thus out of 12x litre of total mixture, 9 litre were taken out.  

Quantity of A in mix. left

= 7x - 9/12x * 7x

= 28x-21 / 4 litre

Quantity of B in mix. left

= 5x- 9/12x*5x  

= 20x-15 / 4 litre

Therefore ratio  

7:9

or x = 3