Solution to this problem?

Question

Could you solve this question for me?
If $10$ years are added to $3/5$ of the age of John, he will be $4$ years younger to the present age of his elder brother who will be $25$ years. What is the present age of John? Thanks in advance.

Answer 1

Let $x$ be the present age of John, then \begin{align} \frac{3}{5}x+10&=25-4\\ \frac{3}{5}x+10&=21\\ \frac{3}{5}x&=11\\ x&=\frac{5}{3}\cdot11\\ x&=\frac{55}{3} \end{align} Therefore, the present age of John is $\cfrac{55}{3}$ years.

Answer 2

Treat it as an equation. Let $x$ be the present age of John. Now $$\frac{3}{5}x+10=21$$ I'll leave the rest up to you.