13.Two pipes can fill the cistern in 5 hours and 12hours respectively,

1.	13.Two pipes can fill the cistern in 5 hours and 12hours respectively, while thethird empty it in 20 hours. If allpipes are open in how manyhours the cistern will be filled.
Answer» Step-by-step explanation: (A and B are filling PIPE and C is empty pipe) If all pipes are KEPT open then unit/hr filled: A+B−C =4+3−6 = 1 units/hr Empty TANK will be filled in T.Ceffiency=121=12 hrs

13.Two pipes can fill the cistern in 5 hours and 12hours respectively, while thethird empty it in 20 hours. If allpipes are open in how manyhours the cistern will be filled.

Answer»

Step-by-step explanation:

(A and B are filling PIPE and C is empty pipe)

If all pipes are KEPT open then unit/hr filled:

A+B−C

=4+3−6

= 1 units/hr

Empty TANK will be filled in

T.Ceffiency=121=12 hrs