A in 6 days, B in 10 — Time & Work Aptitude Question
A in 6 days, B in 10: A can do a piece of work in 6 days and B in 10 days. How long will they take together? Answer and worked solution on CodeKairo.
- Topic: Time & Work
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 45 seconds
Question
A can do a piece of work in 6 days and B in 10 days. How long will they take together?
Options
- 3.75 days
- 4 days
- 4.5 days
- 5 days
Show the answer and the worked solution
Correct answer: A. 3.75 days
Worked solution
- Work = 30 units. A does 5 units/day, B does 3 units/day.
- Together = 8 units/day.
- Time = 30 ÷ 8 = 3.75 days.
Answer: 3.75 days.
The idea
The combined time is always less than the faster worker's time alone — a useful check before selecting an option.
Shortcut. Product ÷ sum: 6 × 10 ÷ 16 = 60 ÷ 16 = 3.75 days.
Common trap. 4 days — 30 ÷ 8 rounded to a whole day out of habit, since most answers in the chapter are integers; the exact 3.75 days is on offer.