Question

A watch loses 6 min and the other gains 4 min daily. They are set right at 3 p.m. After how many minimum number of days, both of them will show the same time?​

Answer 1

Answer:

This is the answer if the question is "after how many days will both the clocks show same time".

But, whether the question is to find number of days in which both the clocks again show 6 O' clock? If so, this cannot be the right answer.

First clock gains 3 min in 1 day.

So, in 72 days, it gains 72×3=21672×3=216 minutes

Second clock looses 7 min in 1 day.

So, in 72 days, it looses 72×7=50472×7=504 minutes

Therefore, in 72 days, 216+504216+504 minutes or 1212 hour difference appears between the clocks and hence both show same time in 12 hour clock.

But, the time will not be 6 O' clock again in both the cloks.

Answer 2

Both clocks will show at the same time after 72 days.

GIVEN: A watch loses 6 min and the other gains 4 min daily. They are set right at 3 p.m.
TO FIND: Minimum number of days both of them will show the same time
SOLUTION:

As we are given in the question,

Clock A: Gains 4 min daily.

Clock B: Looses 6 min daily.

The first clock gains 4 min in 1 day.

So,

In 72 days,

It will gain = 72×3 =216 minutes

Similarly,

The second Clock loses 6 mins in 1 day.

So,

In 72 days

It will gain = 72×7 =504 minutes

Therefore, in 72 days, both the clock shows the same time in the 12-hour clock.

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