Pipes & Cisterns Formula
Pipes & Cisterns formulas and a topic-wise mock test for quantitative aptitude placement exams like TCS NQT, Infosys, and Wipro. Revise, then practice.
Key Pipes & Cisterns Formulas
Pipes & Cisterns Fundamentals - Flow Problems
Pipes and Cisterns problems deal with how quickly containers can be filled or emptied. Filling pipes have positive efficiency, emptying pipes have negative efficiency.
- Filling Pipe: Positive efficiency
- Emptying Pipe: Negative efficiency
- Net Efficiency = Sum of all pipe efficiencies
- Time to Fill/Empty = 1 / Net efficiency
- Example: A fills in 10h, B empties in 8h → Net = 1/10 - 1/8 = -1/40 → empties in 40h
Multiple Pipes - Complex Scenarios
Multiple pipes working simultaneously require careful analysis of the net effect.
- Two Filling Pipes: 1/a + 1/b = 1/total time
- Filling and Emptying: 1/a - 1/b = 1/total time
- Three Pipes: 1/a + 1/b + 1/c = 1/total time
- Example: A fills 12h, B fills 8h → Combined=1/12+1/8=5/24 → 4.8h
Advanced Pipe Problems
Practical applications of pipes and cisterns.
- Example 1: A=10h, B=15h → Combined=1/10+1/15=1/6 → 6 hours
- Example 2: A fills 12h, B empties 8h → Net=1/12-1/8=-1/24 → empties in 24h
- Example 3: A=6h, B=8h, C empties 12h → Net=1/6+1/8-1/12=5/24 → 4.8h
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