Formulas For Pipes & Cisterns

Formulas for Pipes and Cisterns

1. If pipe can fill a tank in x hours , then part filled in one hour = \frac{1}{x}

2. If pipe can empty a tank in y hours , then part emptied in one hour = \frac{1}{y}

3. If pipe A can fill a tank in x hours, Pipe B can empty the full tank in y hours (where y > x). Then, on opening both the pipes, the net part filled in one hour= \frac{1}{x} – \frac{1}{y} OR \frac{xy}{y-x} hours

4. If pipe A can fill a tank in x hours. Pipe B can empty the full tank in y hours (where x > y). Then, on opening both the pipes, the net part filled in one hour= \frac{1}{y} – \frac{1}{x} OR \frac{yx}{x-y} hours.

5. If pipe A can empty a tank in X hours. Pipe B can empty the same tank in Y hours. Then part of the tank emptied in one hour when both the pipes start working together = \frac{1}{x} + \frac{1}{y}