An algebra problem by sara sharma

At present:

$\dfrac{S}{A}=\dfrac{4}{5}$ $\implies$ $A=\dfrac{5}{4}S$ $\color{#D61F06}(1)$

Twelve years from now:

$\dfrac{S+12}{A+12}=\dfrac{5}{6}$ $\implies$ $6S+72=5A+60$ $\implies$ $5A-6S=72-60$ $\implies$ $5\left(\dfrac{5}{4}S\right)-6S=12$ $\implies$ $S=48$

Two years from now:

$S+2=48+2=$ $\color{#D61F06}\boxed{50}$

let initial ages of soham and aarohan be 4x and 5x respectively. Therefore after 12 years, Soham's age will be 4x+12 and Aarohan's will be 5x+12. Therefore 4x+12/5x+12=5/6. Solve for x. x comes out 12. Therefore Soham's present age is 48(4x=4*12) and after 2 years 48+2 = 50