Output of two machines — Caselets Aptitude Question
Output of two machines: Machine A produces 240 units in 8 hours; machine B produces 300 units in 10 hours. Answer and worked solution on CodeKairo.
- Topic: Caselets
- Section: Data Interpretation
- Difficulty: Medium
- Time target: 75 seconds
Question
Machine A produces 240 units in 8 hours; machine B produces 300 units in 10 hours. Both run for 6 hours.
How many units do they produce together?
Options
- 330
- 340
- 350
- 360
Show the answer and the worked solution
Correct answer: D. 360
Worked solution
- A: 240 ÷ 8 = 30 units/hour. B: 300 ÷ 10 = 30 units/hour.
- Together = 60 units/hour for 6 hours = 360 units.
Answer: 360.
The idea
Reduce each machine to a rate before combining. Adding the raw totals would ignore the different running times.
Shortcut. Both machines run at 30 units an hour, so together they are one 60-an-hour machine: 60 × 6 = 360.
Common trap. 330 — scaling B's 300 units by a half (150), as if 6 hours were half its 10-hour run, while scaling A correctly to 180.