Question
Pipe P can fill a tank by itself
in 16 hours, while pipe R can empty the tank in 36 hours when it is full. Together, pipes P and Q can fill the tank in 9 hours. How long will it take for pipes Q and R, working together, to fill the same tank?Solution
ATQ, Let the capacity of the tank = L.C.M of 16 and 36 = 144 units Then, efficiency of pipe βPβ alone = 144 Γ· 16 = 9 units/hour Efficiency of pipe βRβ alone = 144 Γ· 36 = 4 units/hour Combined efficiency of pipes βPβ and βQβ = 144 Γ· 9 = 16 units/hour So, efficiency of pipe βQβ alone = 16 β 9 = 7 units/hour So, combined efficiency of pipes βQβ and βRβ = 7 β 4 = 3 units/hour So, time taken by pipes βQβ and βRβ together to ill the tank = 144 Γ· 3 = 48 hours.
562, 628, 698, ?, 850
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120, 130, ?, 140, 100, 150
What will come in place of the question mark (?) in the following series?
72, 78, 90, ?, 132, 162
71, 79, 88, 152, ?, 393
What will come in place of the question mark (?) in the following series?
7, 20, 59, 176, 527, 1580, ?
140, 146, 170, 224, ?, 470
What will come in place of the question mark (?) in the following series?
60, 110, 224, 463, ?, 1716
What will come in place of the question mark (?) in the following series?
225, 227, 233, 245, 265, ?
8, ?, 29, 57, 113, 225
What will come in place of the question mark (?) in the following series?
555, 430, ?, -320, -1320, -3320Β