Question
A water tank can be filled in 20 minutes by an inlet and
emptied in 30 minutes by an outlet. Calculate the time required to fill half of the tank with both open.Solution
ATQ,
Let total capacity of the tank be 60 litres (LCM of 20 and 30)
Efficiency of inlet = 60 ÷ 20 = 3 litres/minute
Efficiency of outlet = 60 ÷ 30 = -2 litres/minute
Required time = (0.5 × 60) ÷ (3 - 2) = 30 minutes
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