Pipes A, B and C can fill an empty tank in 12 minutes, 24 minutes and 36 minutes respectively. Pipes D and E can empty the full tank in 18 minutes and 72 minutes respectively. If all of them are opened simultaneously, then find the time taken to fill the empty tank. The following are the steps involved in solving the above problem. Arrange them in sequential order.
`(11)/(72)-(5)/(72)=(6)/(72)=(1)/(12)`
The work done by 5 pipes in1 minute.
`=((1)/(12)+(1)/(24)+(1)/(36))-((1)/(18)+(1)/(72))`
`((6+3+2)/(72))-((4+1)/(72))`
The part of tank filled by A,B and C in 1 minute is 1/12,1/24 and 1/36 respectively.
The part of the tank emptied by D and E in 1 minute is 1/18 and 1/72 respectively.

Options

A. CDBA
B. DCAB
C. BCAD
D. DBAC

Answer

A

Explanation

(C),(D),(B ) and (A) is the required sequential order.