Question

A basin can be filled by tap A in 5 hours and by tap B in 8 hours, each tap working on its own. When the basin is full and a drainage hole is open, the water is drained in 20 hours. If initially vthe basin was empty and someone started the two taps together but left the drainage hole open. How long does it take for the basin to be filled?​

Answer 1

Answer:

Is the answer 3.64 hrs

Step-by-step explanation:

Answer 2

•Let volume of basin be V litres

• basin can be filled by tap A in 5

hours

• rate of flow of water through A =

V/5 lit/hr

•similarly, basin can be filled by tap

B in 8 hours

•rate of flow of water through A = V/8 lit/hr

•similarly, basin can be drained by hole in 20 hours

•rate of flow of water through hole = V/20 lit/hr

•Let time taken to fill basin be x

•volume of water released = rate of flow × time

• water through A + water through B - water through hole = V

•Vx/5 +Vx/8 - Vx/20 = V

Vx ( 1/5 +1 /8 -1/20 ) = V

x ( 8 + 5 - 2 )/40 = 1

x (11)/40 = 1

x = 40/11 hours

x = 3.63 hours approx