Aptitude - Clock - Discussion

360- hour * 30-minute * 11/2 = 360-10*30-25*11/2 = 360-162.5 = 197.5.

First, we have to calculate the angle between hour and minute hand.

Time given=10.25.
Angle between two hand=(30*H)-11/2*M.
=(30*10)-11/2*25,
=300-137.5,
=162.5.
Reflex angle = 360-162.5.
=197.5 ie;197 1/2.

They asked reflex angle.ie (360-Shortest angle) = which is basically the biggest angle made by both hands Which is nothing but the clockwise angle.

Now, if it's time 10:25, so the minute hand is at 5 on the clock and the hour hand is above 10 and below 11 to be precise. Slightly below the Middle of 10 and 11.

So, the angle in a clockwise direction will be, from 11 to 5.

It's 180° and from hour hand to 11, it's 15+2.5 ( 15 for the middle of 10 to 11, and 2.5 for slightly below part, analyze in your home clock, everything will be clear).

So, the total angle is 180+15+2.5=192.5°.

The angle between an hour =30°.
Between 10 and 25(5) there are 7 hour.
Therefore 30° * 7 = 210°.
As at 10:25 the hour needle is 25 more than a perfect hour,
Therefore we have to minus 25/2 by 210° (as the angle between a minute is 1/2,
=> 210°- 25/2,
=> 210° -17.5 =192.5.

Simply use formula:

Angle = 30*H - (11*M) / 2 ---> (1).
Reflex Angle= 360 - Angle ---> From (1).

How to calculate the angle between 2 hands of the clock when the time is 9.00 and 12.00 noon. Please explain.

197.5 is the correct answer for this.

(11/2) * minute - 30 * hour = A (angle between hour hand and minute hand).

360- A = reflex angle.

Please explain this in detail.

@Umesh.

Thank you. Nice explanation.