Multiple choice

Two years ago, the age of Rajan was 4 times that of his son. After 5 years, the ratio of ages of Rajan to his son will be 5:2. What is the present age of his son?

  1. 8 years

  2. 14 years

  3. 7 years

  4. 9 years

  5. None of these

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let Rajan's age be R and son's be S. Two years ago: (R-2) = 4(S-2). After 5 years: (R+5)/(S+5) = 5/2. Solving the system: R-2 = 4S-8 => R = 4S-6. Substitute into second: (4S-6+5)/(S+5) = 5/2 => (4S-1)/(S+5) = 5/2 => 8S-2 = 5S+25 => 3S = 27 => S = 9.