sai mohan krishna

• Jul 4th, 2006

 

ans is :20 hrsthe procedure is..............for the first 1 hr the difference between two watches is 3min.hence the difference between both watches is increased by 3min for every 1hr.hence 3min-------------- 1hr60min------------ ?which implies 20 hrs.

Nandini

• Aug 12th, 2006

 

The approach for this problem is very simple

Let us assume that two watches were set at 12.00 midnight

according to problem one watch gains 1 min after one hour and other watch loses two minutes.

So at 1.00Am first watch shows 1.01Am and Second watch shows 12.58Am.

The difference between two watches is 3minutes exactly for 1hour

So When the time difference will be 60minutes exactly for 20hrs

karthi17111987

 Profile Answers by karthi17111987 

• Dec 25th, 2009

 

1st clock +1 min for 1 hr
2nd clock -2 min for 1 hr
so, after 15hr, 1st clock : +15 min than usual time
                      2nd clock::  -30 min than usual time
Hence after 20hr, 1st clock : +20
                             2nd clock:  -40
so, answer is 20hr for 1hr difference.