Aptitude - Clock - Discussion

The formula is 6m-(30h+m/2) m=minutes h=hour.
For example 11:26.

6(26)-(30(11)+(26)/2).
156-(330+13).
156-343.
-187.

If you get a result that is negative, all it means is that the hour hand is ahead of the minute hand, simply multiply the answer by -1 and then subtract that from 360.

Reflex angle = 360-(angle between).

Angle between = (30*hour)-((11*minute)/2).
= (30*10)-((11*25)/2).
= (300-137(1/2)).
= 162 (1/2).

Reflex angle = 360-(162 (1/2)).
= 197 (1/2).

Reflex angle = 360-(angle between hours hand and minute hand).

/*10.25 it can be written as in hrs.*/

Total hours = (10+25/60) = (10+5/12) = (125/12).

Angle traced by hours hand = (125/12)*(360/12) = 312(1/2).

Angle traced by minutes hand = 25*(360/60) = 150.

Angle between 2 hands = 312(1/2)-150 = 162(1/2).

/*The angle formed by a both hands and a perpendicular to the surface at the point of reflection.

Here the surface is circular so ref angle is 360.
*/

Reflection angle = 360-(Angle between 2 hands).

= 360-162(1/2).

= 197(1/2).

Please not that 10.25 cannot be taken as 25 minutes past 10. Rather, it should be 15 mins past 10. Its basic maths.

This table show the movement angle of each hand in each time in a clock.

TIME   Hour   Min   Sec

1 hour   30°   360°   21600°
1 Minute   0.5°   6°   360°
1 Second   1/120°   0.1°   6°

Take simple solution,

After every 12 minutes, Hour clock will move 1 step.
=25 minutes = almost 2 steps moved hour sign from 10 to 10.02.

Now difference between hour & minute clock is 25+8=33 step

1 step = 6 degree than 33 x 6 = 198, answer option near to 198 is given 197 1/2 which is correct.

We can do this question very simply by using following formula..

360-(30H- 11/2M ).

Where H = 10 and M= 25.. easy na ?

We can use this formula too,
Reflex angle = 360-theta.
Theta = 1/2(60h-11m).

We have formula also angle = |(11/2)*min-(30*hour)|.

But, @Karthik, using the formula that you have mentioned, I got wrong answer.