Multiple choice

Rohan's age after 8 years will be two-fifths of his father Mahesh's age at that time. 12 years ago, the ratio of their ages was 1 : 4. What is Mahesh's present age?

  1. 72 yr

  2. 84 yr

  3. 88 yr

  4. 92 yr

  5. 96 yr

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

Let R and M be their present ages. After 8 years, R+8 = 2/5(M+8). 12 years ago, (R-12)/(M-12) = 1/4. Solving this system: 4R-48 = M-12 => M = 4R-36. Substituting into the first equation: 5(R+8) = 2(4R-36+8) => 5R+40 = 8R-56 => 3R = 96 => R = 32. Then M = 4(32)-36 = 128-36 = 92.