Question

Pipe no. 1 can fill the tank in 5 hours and pipe no. 2 in 10 hours. Pipe no. 3 can drain the water and make empty in 15/2 hours. if all the 3 pipes are open all together then the time required for filling the tank completely would be
(A) 4 hours (B) 16 hours. (C) 6 hours. (D) 10 hours

Answer 1

Answer:

option C = 6 hr  is correct

Step-by-step explanation:

Let A,B and C are pipe

Pipe A fill drum in 5 hr =  100 %

Pipe A fill drum in 1 hr =  (100/5) % = 20 %

Pipe B fill drum in 10 hr =  100 %

Pipe B fill drum in 1 hr =  (100/10)% = 10 %

Pipe C empty drum in 15/2 hr =  100 %

Pipe C empty drum in 1 hr =  ((100/15)×2) % = 200/15 % = 40/3 %

Drum filled in one hour while all the pipes are open = ( 20 + 10 - 40/3 ) %

                                                                                       = ( 30 - 40/3 ) %          

                                                                                       = ( (90 - 40) / 3 ) %

                                                                                       = ( 50 / 3 ) %

So

Drum filled in 1 hr = (50/3) %

Multiplying  by 6 on both sides we get

Drum filled in 6 hr = (50/3)×6 % = 100 %

Thus we required 6 hours to fill the drum while all the pipes are open.

So option C = 6 hr  is correct

Answer 2

Step-by-step explanation:

find the HCF of the following numbers using the division method. 504 and 663