Question

Q. The age of Ravi 10 years ago was thrice the age of Kiran. Ten years hence, Ravi’s age will be twice that of Kiran. The ratio of their present ages is :

• A.
  $7:3$
• B.
  $3:5$
• C.
  $9:17$
• D.
  $2:7$

Answer 1

The correct option is A

$7:3$
Explanation:

Let the present age of Ravi and Kiran be R and K, respectively.
Ten years ago, $(R-10)=3(K-10)orR-3K=-20\dots ..\left(i\right)$
Ten years hence, $(R+10)=2(K+10)orR-2K=10\dots ..\left(ii\right)$

Subtracting eqn (i) from (ii), we get $K=30$. Substitute this value of K in any of the two equations to get $R=70$. Hence, the required ratio will be $70:30=7:3$.