The average age of Abhay, his wife and their child 6 years ago was 42 years and that of his wife and their child 8 years ago was 30 years. Find the present age of Abhay.

6 years ago, average age of Abhay, wife, and child was 42, so their total age was 42 × 3 = 126. Their present total age is 126 + 18 = 144. 8 years ago, average age of wife and child was 30, so their total age was 30 × 2 = 60. Their present total age is 60 + 16 = 76. Abhay's present age = 144 - 76 = 68 years. Option B (63) incorrectly subtracts 5 years, option C (64) uses wrong base, and option D (66) miscalculates the difference.