Give solution

Question

 Swimming pool has 4 inlet pipes.Each pipe can fill the swimming pool in 15 minutes. How long will it take to fill up the swimming pool if all 4 pipes were opened simultaneously

Answer 1

t represents the time all four are open

 

t/15 + t/15 + t/15 + t/15 = 

4t/15 = 1

4t = 15

t = 3.75