Question

Two watches, one of which gains 1 min. and other looses 1 min. daily, were set correctly at noon on the first January 1978. When did the watches indicate the same time after January 1978?

• A. Dec. $27,1978$ midnight
• B. Dec. $26,1978$ noon
• C. Dec. $25,1978$ noon
• D. Dec. $28,1978$ noon

Answer 1

The correct option is B Dec. $26,1978$ noon

One of the two clocks looses one minute and the other gains one minute daily.

After 60 days, one watch gains 60 minutes and other looses 60 minute.

So, $60\times 6=360$ minutes will be gained by one watch and other will loose 360 minutes after 360 days.

And both the watches will show a time as 6 o'clock, since subtracting 6 hrs from 12 will result into 6 and adding 6 hrs to 12 noon will also result into 6.

So, after 360 days, both the watches will show same time.

As there are total 365 days in a year, so from January 1st the 360th day will be December 26.

Hence, on December 26, 1978 noon, the watches will show the same time.