Question

two pipe fill an empty tank separately in 90 minutes and 60 minutes respectively,while a third pipe can empty the tank in 45 minutes.If all the three pipe are opened togather,then in how much time the tank shall fill complete?​

Answer 1

Answer:

18 minutes

Step-by-step explanation:

LCM of 90 , 60 and 45 is 180

Pipe A takes 90 minute to fill it so it fills 1/90 tank in 1 minute = 2/180

Pipe B takes 60 minute to fill it so it fills 1/60 tank in 1 minute = 3/180

Pipe C takes 45 minute to fill it so it fills 1/45 tank in 1 minute = 4/180

If all of the pipes fill together than they fill $\frac{2+3+4 = 10}{180}$per minute

So the total time taken will be 180/10 which is 18 minutes