Four pipes fill a cistern in 15,20,30 and 60 hours.The first was opened at 6 am,the second at 8 am,third at 10 am and fourth at noon.When will the reservoir be full?

• 2 PM
  
  If the cistern was filled after x hrs from 6 AM, Then
  
  x/15 + (x-2)/20 + (x-4)/30 +(x-6)/60 =1
  
  solving , we get
  x=8 hrs
• 12 years agoHelpfull: Yes(10) No(5)
• x/15 + (x-2)/20 + (x-4)/30 +(x-6)/60 =1
  
  ans 8
• 10 years agoHelpfull: Yes(0) No(0)