The difference between the ages of Rohit and Axar is $12\text{ years}$. If the ratio of their ages is $3:5$, what is the age of Axar?

Let the current age of Rohit be $3x$ and the age of Axar be $5x$, where $x$ represents the common ratio multiplier.
According to the question, the difference between their ages is $12\text{ years}$:

$$5x-3x=12$$

$$2x=12⟹x=6$$

Now, calculate the age of Axar:

$$\text{Age of Axar}=5x=5\times 6=30\text{ years}$$