Tap A and Tap B can fill a water tank in 3 and 4 hours respectively. A tap C…
2025
Tap A and Tap B can fill a water tank in 3 and 4 hours respectively. A tap C can empty the tank in 6 hours. If all the three taps are opened together, then the tank will be filled in?
- A.
2(⅖) h
- B.
5(2/7) h
- C.
3(⅗) h
- D.
5(1/7) h
Attempted by 35 students.
Show answer & explanation
Correct answer: A
Step 1: Find individual rates.
A fills 1/3 tank/hour; B fills 1/4 tank/hour; C empties 1/6 tank/hour (use negative rate for emptying).
Step 2: Compute combined rate.
Combined rate = 1/3 + 1/4 − 1/6 = 5/12 tank/hour.
Step 3: Find time to fill the tank.
Time = 1 ÷ (5/12) = 12/5 = 2 2/5 hours = 2 hours 24 minutes.
Answer: 2(2/5) h (2 hours 24 minutes).