Tap A fills a pool in 6 hours and tap B fills it in 3 hours. How long do they take together?
Answer and explanation
Correct answer: D. 2 hours
- Step 1: In one hour A fills 1/6 and B fills 1/3 of the pool. Step 2. Together: 1/6 + 2/6 = 1/2 of the pool per hour. Step 3. The whole pool takes 2 hours. Answer: 2 hours. Why not the others: 4 hours 30 minutes: This is the mean of 6 hours and 3 hours. 9 hours: This adds the two times together. 3 hours: This is the difference of the two times.
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