The task is to generate the correct answer for a given math problem.

[EX Q]: Problem: the ratio between the sale price and the cost price of an article is 12 : 7 . what is the ratio between the profit and the cost price of that article ?
[EX A]: 5 : 7

[EX Q]: Problem: a cycle is bought for rs . 900 and sold for rs . 1080 , find the gain percent ?
[EX A]: 20 %

[EX Q]: Problem: roy is now 6 years older than julia and half of that amount older than kelly . if in 4 years , roy will be twice as old as julia , then in 4 years what would be roy ’ s age multiplied by kelly ’ s age ?
[EX A]:
10