UPSC CAPF AC 2017 Paper

Let, present age of father = F years and present age of son = S years According to the question
(F-1)= 4(S-1)
⇒F-1 = 4S-4
⇒ F-4S= -3 .......(i)
and (F+6) = 2(S+6) + 9
⇒ F+6 = 2S +12+9
⇒F-2S=21-6
⇒F-2S = 15 ....(ii)
Now, solving Eqs, (i) and (ii) we have F= 33 Years and S = 9 Years
∴ Ratio of their present ages = 33:9 = 11 : 3