Question

7. A man is twice as old as his son. 18 yr ago, the man was three times as old as his son. Find the present age of the man. RRB NTPC (Phase-1) 2016 (1) 36 yr (2) 18 yr (3), 72 yr (4) 54 yr

11th - 12th Class

Maths

Solution

4.0 (1 ratings)

7. (3) Let the ages of the man and his son be ( 2 x ) and ( x ) yr, respectively. According to the question, [ begin{aligned} & 2 x-18=3(x-18) Rightarrow & 2 x-18=3 x-54 Rightarrow & 3 x-2 x=54-18 Rightarrow x=36 end{aligned} ] Thus, present age of man ( =2 x=2 times 36 ) [ =72 mathrm{yr} ]