Aptitude - Clock - Discussion

1) For 12 hrs 360 degree (for 1 hr 30 degree) for 10 hrs 300 degree & for 25 min converted in to hrs ie ( 25 min/60 min*30 degree)=(25/60*30)12.5 degree total-300+12.5=312.5 degree.

2) for 60 min 360 degree for 25 min 150 degree we get 1)312.5 degree & 150 degree
diff 162.5 deduct rom 360 162.5 ans-197.5 deg.

I have made a formula to calculate clock angle.

(h-(m/5))*30 + m/2 (for calculating ordinary angle)
360 - (this formula for calculating reflex angle)

Hope it Helps!

How you get 125/12?

The angle b/w 10 & 5(10:25) is 150.

For 25 min,hr hand moves 12.5 degrees.the actual angle now is 150+12.5=162.5.To calculate reflex angle 360-162.5=197.5

For simple understanding,let's assume the time is now 12.we can say the angle b/w hr hand & min hand is 0 or 360(reflex angle). At 1'o clock the angle is 30 or 330(reflex).likewise at 10:25 the angle is 162.5 or 197.5.

How did you get 162.5 or 197.5? @A.Margaret.

Thanks all for the given explanation.

I think, it's 197.5 deg.

For 1 deg min hand ---hour hand rotates by 1/12 deg.
So for 10 hours, the hr hand rotates by 10*30=300 deg.
Again for 25 min --- min hand rotates by ---- 25*6 = 150 deg.
So for 150 deg rotation of min hand hour hand rotates by 150/12 = 12.5 deg.
So total hour hand rotation is 300+12.5 = 312.5 deg.
Now the angle left to rotate to complete 1 full rotation is 360-312.5 = 47,5 deg.
The reflex angle will be 150+47.5 = 197.5 deg.

It is asked to find a reflex angle not obtuse angle so the given answer is 100% right.
Thank You.

The angle between hand at 10 hr & 25 /Min is 210,
But hr hand passed 12.5° more (30* in 60 Min multiplied by 25 Min),
Hence net angle 210 - 12.5 = 197.5°.

Reflex angle- the angle is more than 180 and less than 360 ° is called reflex angle-

The formula for this question-
M=2/11(t1*30+-∠),
∠= angle,

Form this question.
25=2/11(10*30+-∠),
25*11/2=300+-∠,
Mode
|275/2-300|=∠,
162.5=∠,
∠=360-162.5,
∠=197.5.

We can find the angle between two hands with the help of bellow formula ( x*30) - (y*11)/2.
Here x is 10 and y is 25.
So by applying bellow formula, the angle between two hands is 162.5,
Now, angle at 10 'o clock is 300,
So, the reflex angle is 300- 162.5 = 197.5.