2 pipes are running conitinuouslt to fill a tank. The 1st pipe can fill the tank in 5 hours by itself and the second one by itself could have filled in 20 hours. But the operator failed to realize that there was a leak in the tank from the beginning which caused a delay of one hour in the filling of the tank. Find the time in which the leak would empty a filled tank.
option
a) 15 hours
b) 20 hours
c) 25 hours
d) 40hours
e) 30 hours

• The two pipes can fill 1/5 and 1/20 parts in one hour, so together they can fill
  1/5+1/20= 1/4 part in one hour, so in 4 hours the pipes can full the tank, but due to leak , there is one hour delay, which means= 4+1= 5 hrs to fill.
  now, 1/5+1/20-1/x = 1/5, on solving x = 20 hrs
• 10 years agoHelpfull: Yes(6) No(0)
• 20 hrs/
  1/5 +1/20= 1/4
  1/4-1/L=1/5
  L=20hrs
• 10 years agoHelpfull: Yes(0) No(0)