Time and work


If A can do a piece of work in n days then in 1 day’s work \frac{1}{n}
If A’s day’s work is 1/n than A can finish the work in n days.

Pipes & cisterns

Inlet- a pipe connected with a tank/cistern that fill it is known as an inlet.
Outlet- a pipe connected with a tank/cistern, emptying it is known as an outlet

1) If a pipe can fill a tank in x hours , then part filled in hour = \frac{1}{x}
2) If pipe can empty a full tank in y hour than part emptied in 1 hour= \frac{1}{y}
3) If a pipe can fill a tank in x hours & another pipe can empty the full tank in y hours. Than an opening both the pipe the net part filled/emptied

Where y<x filled in 1 hour = (\frac{1}{x} - \frac{1}{y})
Where x>y emptied in 1 hour = (\frac{1}{y} - \frac{1}{x}) part.