Q. Two years ago, the ratio of Ram's and Mohan's age was 3 : 2 and at present 7 : 5. What are their present ages?

Explanation:

The ratio of Ram's and Mohan's present age is 7 : 5.
Let us assume the present ages of Ram and Mohan are 7Y and 5Y years.
2 Years ago the age of Ram and Mohan will be 7Y - 2 and 5Y - 2 years.
According to question,
Two years ago, the ratio of Ram's and Mohan's age was 3 : 2, then
(7Y -2)/(5Y - 2) = 3/2
⇒ (7Y -2) x 2 = 3 x (5Y - 2)
⇒ 14Y - 4 = 15Y - 6
∴ Y = 2
Hence, their present ages = 7 x 2 = 14 years and 5 x 2 = 10 year