Peter is 15 years older than Kenneth. If 5 years ago, Peter was 3 times as old as Kenneth, then find Peter's present age?
A. \(32.5\) years B. \(27.5\) years C. 25 years D. \(24.9\) years
Correct Answer: B
Explanation
Let Kenneth's percentage age \(= K\). and Peter's present age \(= P\) \begin{aligned} & P = K +15 \ldots \ldots(1) \\ &( P -5)=3( K -5) \end{aligned} \begin{aligned} & P -5=3 K -15 \\ & P -3 K =-15+5 \\ & P -3 K =-10 \\ &-2 K =-10-15 \\ &-2 K =-25 \\ & K =\frac{-25}{-2}=12.5 \end{aligned} Put K \(12.5+15=27.5\) yrs
