Aptitude - Clock - Discussion

Formula for cal angle = 11/2*mins-30*hrs.

Therefore 11/2*25-30*10 = 137.5-300 = 163.5.

Reflex angle = 360-163.5 = 197.5 answer.

The formula is wrong. The correct formula is:

The angle between the hands of the clock = (60xH - 11xM)/2.

But in the above question, according to formula (60Xh-11Xm)/2.

(60X10-11X25)/2.

(600-275)/2.

375/2.

= 162.5.

Reflex angle = 360-162.5 = 197.5.

So, simple when the question asks between 1-11.

Take a formula as 11:60 - Time.

11:60 - 10:25 = 1:35 is the answer.

10:25 = 10 hrs + 25 min. Therefore, total angle between them.

[angle at 10 hrs (=60 deg) + angle during 25 min movement (=150(min needle)-12.5(hrs needle) = 137.5 deg)]

= 60 + 137.5 = 197.5 or 197(1/2) degree.

Refer explanation below:

At 10 hrs, angle between them = 60 degree.

During 25 min movement both needle will move. At 25 min minute needle will make an angle = 25 x 30 = 150 degree.

Simultaneously, hrs needle also will move an angle = 12.5 degree. (as hrs needle make 360 degree in 12 hrs or 720 min. Therefore, in 25 min, angle = 25x360/720 = 12.5 degree.).

There is no easy way to understand in spite of this explanation.

I want clear definition of reflex angle and formula.

What's the formula to calculate reflex angle if it is greater than 180 degrees? Anyone who know please tell me.

Reflex angle is nothing but an angle greater than 180 degrees.

Equation for the angle of the hour hand,

(Hour Angle) = (60H+M)/2.

Where, H= Hour.

M is the minutes past the hour.

And, Equation for the angle of the minute hand, (minute Angle) = 6M.

For Example:

10.25.

(Hour Angle) = (60*10+25)/2 = 312.5.

(Minute Angle) = 6*25 = 150.

Reflex angle = 360-(312.5-150) = 197.5.

Hi everyone, Please help me to solve clock problems because I am unable to understand the concept.