Time gained in 1 hour = 6 minutes
Time gained in 6 hours = (6 × 6) minutes = 36 minutes
After 6 hours, the correct time is 11 : 00 am and the watch will show 11 : 36 am.
Workspace
A watch gains 5 seconds in 3 minutes and was set right at 8 AM. What time will it show at 10 PM on the same day ?
The clock has totally gained 16 minutes and 40 sec. i.e. 1000 seconds in 160 hrs. In order to show the right time, the clock has to gain only 6 min i.e. 360 seconds. Just apply the chain rule, the clock gained 1000 sec in 160 hrs, it will gain 360 sec. In 360 × 160/1000 = 288/5 hrs i.e. 57 3/5. Adding 57 hrs & 36 minutes in Monday 5 p.m. you get 2:36 a.m. on Thursday.
Workspace
A clock is set right at 10 a.m. on Monday. The clock loses 15 min. in 24 hrs. What will be the true time when the clock indicates 4 am on the following Saturday?
From 10 am on 1st day to 4 am on 5th day is total 114 hours. When a clock loses 15 min, then 23 hours 45 min of this clock are the same as 24 hours of correct clock i.e. 95/4 hours of this clock = 24 hours of correct clock. 95/4 hours of this clock =((24×4/95)×114) hours of correct clock = 115.2 hours of correct clock which is equal to 115 hours 12 minThe correct time is 5:12 am.
Workspace
At what time between 2 and 3 o’clock will the hands of a clock be together?
At 2 o’clock, the hour hand is at 2 and the minute hand is at 12, i.e. they are 10 min spaces apart.
To be together, the minute hand must gain 10 minutes over the hour hand.
Now, 55 minutes are gained by it in 60 min.
10 minutes will be gained in (60/55)*10min=10(10/11)min
The hands will coincide at 10(10/11) min. past 2.
Workspace
Imagine that your watch was correct at noon, but then it began to lose 30 minutes each hour. It now show 4 pm but it stopped 5 hours ago. What is the correct time now = ?
The watch loses (1/2) hour each hour. So, it must have take 8 hours to show 4 pm from 12 noon.
Thus, it stopped at 8 pm.
So, the correct time is 5 hours ahead of 8 pm, i,e., 1 am.
Workspace
There are two clocks, both set to show 10 pm on 21st January 2010. One clock gains 2 minutes in an hour and the other clock loses 5 minutes in an hour. Then by how many minutes do the two clocks differ at 4 pm on 22nd January 2010 ?
One clock show 10 pm, on 21st January 2010
One clock gains = 2 minutes
Other clock loses = 5 minutes
Time period between 10 pm and 4 pm = 18 hours
∴ Required difference
= (2 × 18 + 5 × 18 ) minutes
= 126 minutes
Workspace
A clock is started at noon. By 10 minutes past 5, the hour hand has turned through:
The hands of a clock point in opposite directions (in the same straight line) 11 times in every 12 hours. (Because between 5 and 7 they point in opposite directions at 6 o’clcok only).
So, in a day, the hands point in the opposite directions 22 times.
Workspace
A clock gains 10min in every 24hrs. It is set right on Monday at 8a.m. What will be the correct time on the following Wednesday, when the watch indicates 6p.m
