The ratio of the ages of Pooja and Mohit is $4 : 5$, and their ages add up to 54 years. How old is Mohit?

Explanation

1. 01

   Total parts = $4 + 5 = 9$; one part = $54 \div 9 = 6$ years.

2. 02

   Mohit = $5 \times 6 = 30$ years.