Aptitude - Clock - Discussion

Discussion Forum : Clock - General Questions (Q.No. 2)
2.
The reflex angle between the hands of a clock at 10.25 is:
180°
192 1 °
2
195°
197 1 °
2
Answer: Option
Explanation:

Angle traced by hour hand in 125 hrs = 360 x 125 ° = 312 1 ° .
12 12 12 2

Angle traced by minute hand in 25 min = 360 x 25 ° = 150°.
60

Reflex angle = 360° - 312 1 - 150 ° = 360° - 162 1 ° = 197 .
2 2 2

Discussion:
269 comments Page 3 of 27.

Prasanna Kumar said:   5 years ago
Angle made by hour hand for every hour is 360/12 = 30.
Angle made by hour hand for every minute is 30/60 = 0.5,
Angle made by hour hand when the time is 10 is 300.
Angle made by hour hand when the time is 10:25 is 300+(25*0.5) = 312.5,
Angle made by minute hand when the time is 10:25 is 30*5 = 150,
Angle between the hour hand and minute hand at 10:25 is 312.5-150 =162.5,
The reflex angle between the hour and minute hand at 10:25 is 360-162.5 = 197.5.
(2)

Dony David said:   8 years ago
Use this formula (max of the problems will be solved).

Angle=30h-11/2(m)
so acc to given values the time is 10:25,
so h=10,m=25
on solving
angle=30(10)-11/2(25)
=300-11 x12.5
=300-137.5
=162.5(this is internal angle).

Therefore==> reflex=360(this is total angle of clock)-162.5,
=360-162.5,
=197.5,
==>197 1/2 deg.

Navnath Dombale said:   1 decade ago
Please read. Its important I'm Navnath Dombale.

Simply 10:25 means angle covered in 25 m = 12.5° (after 60 m = 30°.

For example if both hands started 12:00 then after 60 m hrs hands reaches at 1:00. So in 60 m = 30°.

So 1 m = 0.5°.

25 m means min it hand on 5. So difference in angle is (5-6-7-8-9-10 = 5 hrs angle = 150°+12.5° = 162.5°.

Reflect angle = 360°-162.5° = 197.5°.

Ans = 197.5°.

Fahad said:   9 years ago
This is very simple method.

10.25 means hour hand is at 10 and the minute hand is at 5. So angle between them is 10 - 5 = 5hrs.
Since 12hrs is 360 degree.

1hr = 30degree. So, 5 * 30 = 150degree. But when it is 25minutes.

We have a small angle that has to be added ie. 25minutes = 12. 5degree.
Since 1minute is 1/2degree.

Therefore 150 + 12.5 = 162.5.
But they asked reflex angle so, 360degree - 162.5degree = 197.5degree.

Sachin Kumar H S said:   5 years ago
Guys, I have another formula applicable to find the angle between two hands of the clock,
Angle.

A = ((60 * hour given) - (11 * mins given))/2.

Therefore from the above problem - given 10:25.

A = ((60*10) - (11*25))/2.
After solving the above equation we get Angle A=162.5 Deg.
Now reflex angle = 360 - angle obtained.
= 360 - 162.5.
= 197.5 Deg.

Priya said:   1 decade ago
Calculation for 125/12 are correct ...as sharad said the formula must be reflex angle= 360(deg)- [ang traced by hour hand(deg)- ang traced by min hand(deg)]........ since we consider evreything based on 12 o'clock ..and so subtract 2 hrs from it(10 o'clock) ..also subtract 25 mins in reverse (25 min)....see a clock for reference.... think logically may be...thanks friends for your discussion...

B.Vamsi Srinivas said:   1 decade ago
Have a look at my solution once...

Time 10:25

Reflex Time...
11:60
-10:25
~~~~~~~
1:35

formulae to find angle

Angle = 11*(m)
---- - 30(h)
2
m = minutes
h = hours

so
now

11*35
= ----- - 30* 1
2


385 - 60
= --------
2

325
=---
2

1
=167 ---
2

Correct me if I'm wrong.

MOHIT KUMAR said:   8 years ago
Solution:

12 hrs=360 degree.
means 10.25 hrs = 625 mins.
Total angle covered by 10.25 hrs = (625/720)*360 = 312(1/2) degree //Angle from 12 to 10:25.

Now angle for min hand 25 mins = (25/60)*360= 150 degree.

Reflex angle = 150+ remaining angle between 10:25 and 12.
= 150+(360-312(1/2)).
= 150+47.5.
= 197.5 degree.

Thank You.

Durai said:   8 years ago
1 min = 0.5 deg, 1hrs =30 deg. becz. 12h = 720 min, clock 12h = 360 deg.

Reflect angle mean measure angel more than 180 deg side.
So on clock 10.25 hrs mean the clock needle lies between 10-5.
So from 5 to 10 measure angle hours is 7 hr(Becz reflex angle method)=7X30 deg=210 deg.
25 min = 25X0.5 deg =12 1/2 deg.

Reflex angle method
Subtract hours by minutes (10hrs-25min) =210-12.5 = 197.5

Zain ali said:   1 decade ago
Hour hand is at 10.25 and min hand is at 5.
Forget about min hand. Take 10.25 o clock as a refrence point and move hour hand towards 5 o clock.Here 5 is final point suppose.So hour hand will travel a total of 6.35 hours.In each hour angle formed if 30.So 6.35*30 = 190'30". MY answer is wrong but i dont think that i have made mistakes.
PLEASE DO TELL ME WHAT I AM DOING WRONG........


Post your comments here:

Your comments will be displayed after verification.