a tank is filled in 5 hr by three pipes A B C the pipe C is twice as fast

suppose A alone can fill tank in x hours than
A+B+C=1/5
1/x+2/x+4/x=1/5
7/x=1/5
than 1/x=1/35
then x= 35
ans:35
11 years agoHelpfull: Yes(6) No(0)
Suppose pipe A alone takes x hours to fill the tank.

Then, pipes B and C will take x and x hours respectively to fill the tank.
2 4
1 + 2 + 4 = 1
x x x 5
7 = 1
x 5
x = 35 hrs.
11 years agoHelpfull: Yes(3) No(0)
sorry for incomplete ques...its the pipe c is twice as fast as b and b is twice as fast as a
11 years agoHelpfull: Yes(2) No(0)
C is twice as fast as B=> C=2B
B is twice as fast as A=> B=2A => A=B/2
(1/A)+(1/B)+(1/C)=(1/5) .... since tank can be filled in 5hrs
(2/B)+(1/B)+(1/2B)=(1/5)
=> B=35/4 => 8 hrs 9min
11 years agoHelpfull: Yes(2) No(2)
options are:-
50
51
52
53
11 years agoHelpfull: Yes(0) No(1)

a tank is filled in 5 hr by three pipes A,B,C.the pipe C is twice as fast as B and is twice as fast as a.how much time will pipe A alone take to fill the tank