Husband, wife and child — Problems on Ages Aptitude Question
Husband, wife and child: Three years ago the average age of a husband, wife and child was 27. Answer and worked solution on CodeKairo.
- Topic: Problems on Ages
- Section: Quantitative Aptitude
- Difficulty: Hard
- Time target: 120 seconds
Question
Three years ago the average age of a husband, wife and child was 27. Five years ago the average age of the wife and child was 20. What is the husband's present age?
Options
- 35
- 40
- 42
- 45
Show the answer and the worked solution
Correct answer: B. 40
Worked solution
- Three years ago: total = 3 × 27 = 81. Now: 81 + 9 = 90.
- Five years ago: wife + child = 2 × 20 = 40. Now: 40 + 10 = 50.
- Husband = 90 − 50 = 40.
Answer: 40.
The idea
Bring every group forward to the present before subtracting, adding one year per person per year. Mixing two different reference times is the trap here.
Shortcut. Align both groups at five years ago instead: the three totalled 81 three years ago, so 81 − 6 = 75 two years earlier. Take off the wife and child's 40: the husband was 35 then and is 40 now.
Common trap. 35 is the husband's age five years ago; aligning the groups in the past and forgetting to add the five years back yields it.