2015 · Q97
Four years ago, the average age of A and B was 18 years. Now the average age of A, B and C is 24 years. After 8 years, the age of C will be
Elementary MathematicsNumber System
- A32 years
- B28 years
- C36 years
- D40 years
Explanation
This is an average-age shift problem. Four years ago A and B averaged 18, so their total was 36 then; each has aged 4 years, so A + B = 44 now. Now A, B, C average 24, so their total is 72, giving C = 72 - 44 = 28 at present. After 8 more years C will be 36. The trap is option (a) 32, from forgetting to age A and B forward by 4 years. Hence option (c).