4
Answer: BSet 3: Linear Equations (Advanced)
Explanation
Two pipes can fill a tank. Pipe A alone fills it in 6 hours, Pipe B alone in 4 hours. If both pipes are open, how long will it take to fill the tank?
How many hours to fill the tank?
A.
3
B.✓ Correct
2.4
C.
2
D.
5
Detailed Explanation
Choice B is correct. Rate A = 1/6 tank/hr, Rate B = 1/4 tank/hr. Combined: 1/6 + 1/4 = 2/12 + 3/12 = 5/12 tank/hr. Time = 1 ÷ (5/12) = 12/5 = 2.4 hours.
Key Steps:
•
The correct answer is 2.4
Why others are wrong:
A: Choice A is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.
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