Pipes and Cisterns
Tested in 3 real MPSC questions across 1 year (2021–2021). See it in context on the interactive Concept Graph →
Years it was asked
What you need to know first
LCM methodFraction arithmeticReciprocal calculationsFraction subtraction
Real questions that test this
एक नलिकेने एक टाकी 4½ तासात भरते. पण बुडाशी असलेल्या गळतीमुळे ती भरण्यासाठी 1½ तास जादा लागतात. जर ही टाकी पूर्ण भरलेली असेल तर गळतीमुळे ती रिकामी व्हायला लागणारी वेळ निवडा. A pipe can fill the tank in 4½ hours. But due to leakage at the bottom, it takes 1½ hours more to fill it. If the tank is full select the time that it will require to get emptied due to leak.
1)18 hr.✓ Correct
2)12 hr.
3)9 hr.
4)10 hr.
Normal time = 4.5 hrs. Time with leak = 4.5 + 1.5 = 6 hrs. Let leak empty in x hours. Net rate = (1/4.5) - (1/x) = 1/6, solving gives x = 18 hours.