Mathematics
NULL
Medium
Question
A tank is 7 m long and 4 m wide. At what speed should water run through a pipe 5 cm broad and 4 cm deep so that in 6 hours 18 minutes the water level rises by 4.5 cm?
A
12 km/hr
B
10 km/hr
✓ Official correct answer
C
14 km/hr
D
None of these
Community credibility
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A
12 km/hr
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B
10 km/hr
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C
14 km/hr
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D
None of these
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Explanation
Volume = 7×4×0.045 = 1.26 m³; pipe area = 0.002 m²; time = 6.3 h. Speed = 1.26/(0.002×6.3) = 100 m/h = 0.1 km/h, not 10 km/h.