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? Choose the correct choice from the following answers:
A) 1PM B) 2PM C) 3PM D) 4PM E) 5PM
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   2PM   ANSWER:2PM
<result>B</result>
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?