Multiple choice

5 years ago ratio of age of father and mother was 6:5. 8 year hence ratio of age of mother and son will be 4:1. If son has celebrated his second birthday two years ago, find the sum of present ages of father, mother and son.

  1. 78 years

  2. 91 years

  3. 112 years

  4. 98 years

  5. None of these

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

5 years ago, F:M = 6:5, so 5(F-5) = 6(M-5), giving 5F = 6M-5. 8 years hence, M:S = 4:1, so M+8 = 4(S+8), giving M = 4S+24. The son celebrated his 2nd birthday 2 years ago, so his current age is 4. Solving: M = 4(4)+24 = 40, then 5F = 6(40)-5 = 235, so F = 47. Sum = 47+40+4 = 91 years.