Survesh was thrice as old as Sneha 5 years back Survesh will be 7 3 times as old as Sneha 5 years he...........

Explanation:

Let  age of sneha=x

age of survesh=y

5 years back 

(y-5)=3(x-5)

y-5=3x-15

3x-y=10      ---------------------------(1)

5years hence

(y+5)=7/3(x+5)

3y+15=7x+35

7x-3y=-20    -------------------------------(2)
solving equations

x=25

So age of sneha=25yrs.