Question

A watch was set correct at 12'O clock. It loses 10 minutes per hour. What will be the angle
between the two hands of the clock after 1 hour ?

Answer 1

Given:

The clock loses 10 minutes per hour

Here, the clock shows only 50 minutes for 60 minutes( in 1 hour)

The watch show the time 12 : 50, after 1 hour



Formula ,To find the angle between hour hand and minutes at H hours M minutes =30H – 11/2 M


The angle between the two hands of the clock after 1 hour

=30 x 12 – 11/2 x 50

= 360° - 11×25

=360º – 275º = 85º

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Hope this will help you.....

Answer 2

For finding the angle first of all  , do the time calculation.
As from the data we know that clock is at 12'O clock and is loosing the 10 minutes per hour  So the time shows by watch after 1 hour will be 12:50 (because of loosing ten minutes)
In order to find the angle b/w both hands of clock let consider the  hour hand of clock is H and minute hand is M. So we know that
angle between both hands = 30H - 11/2* M
Angle between both hands after 1hour will be = 30 (12) - 11/2 * 50 

So the angle will be = 360 degree -275 degree = 85 degree

So at 12:50(after 1 hour) the angle between both hands will be of 85 degree.