Tank has 2 pipes. Pipe A can empty in 30min, pipe B can empty in 25min. if tank is 5/6 filled and both pipes are open, time taken to empty the tank is?

Question

Linear equation

Answer 1

If pipe A empties the tank in 30 minutes, this means that it removes 1/30 of the tank every minute.  If pipe B empties the tank in 25 minutes, this means that it removes 1/25 of the tank every minute.  When two people, pipes, machines, etc. work together, you find the combined rate by adding the individual rates.

 

1/30 + 1/25 = 5/150 + 6/150 = 11/150

 

Therefore, combined, they remove 11/150 of the tank every minute.

 

If the tank is 5/6 full, we need to figure out how many times 11/150 goes into 5/6, since that will be the number of minutes it takes to empty the tank.

 

5/6 ÷ 11/150 = 5/6 × 150/11 = 125/11 or 11.36 minutes.

Answer 2

t represents the amount of time working together

t/30 + t/25 = 5/6

 

Can you solve for t?