Six years ago, the average age of a husband and his wife was 20 years. Today, the average age of the husband, the wife and their child is 20 years. How old is the child?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 8 years
The total age of the couple six years ago is moved to today by adding 6 years for each of the two; the rest of today’s family total is the child’s age.
Husband \(+\) wife six years ago \(=2\times20=40\) years
Husband \(+\) wife today \(=40+2\times6=52\) years
Husband \(+\) wife \(+\) child today \(=3\times20=60\) years
Child’s age \(=60-52=8\) years