Mathematics
NULL
Medium
Question
A leak empties a cistern in 20 minutes. A tap admits 4 litres/min and with both open the cistern empties in 24 minutes. How many litres does the cistern hold?
A
480 liters
✓ Official correct answer
B
600 liters
C
720 liters
D
800 liters
Community credibility
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A
480 liters
No member explanations yet for this option.
B
600 liters
No member explanations yet for this option.
C
720 liters
No member explanations yet for this option.
D
800 liters
No member explanations yet for this option.
Explanation
4/C = 1/20 + 1/24 = 11/120 ⇒ C = 480 litres.