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:
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 | 1° | . |
| 2 | 2 | 2 |
Discussion:
269 comments Page 5 of 27.
Charan said:
1 decade ago
As venu said 10.25 can be simplified easily 10 in hrs and 25 in min so, totally in hrs it is 10+(25/60)=125/12.
Firstly 10.25 indicates the time which is exactly 10 but 25 min fast.
We have to subtract the angle subscribed by min hand.
Lastly reflex angle is the angle >180 and the remainin angle subtended by t, other than the acute angle.
Firstly 10.25 indicates the time which is exactly 10 but 25 min fast.
We have to subtract the angle subscribed by min hand.
Lastly reflex angle is the angle >180 and the remainin angle subtended by t, other than the acute angle.
Ashwin Kashyap said:
1 decade ago
Hi IndiaBix Users,
It is a Cool Question;Just we have to apply the concept exactly to the analysis in this problem.
Thank You for all those who helped the solvers.
We usually measure angles in anti-clockwise direction.
So,the angle which is the major part in the rotation is measured as reflex angle,and mostly it is between 180 and 360 degrees.
It is a Cool Question;Just we have to apply the concept exactly to the analysis in this problem.
Thank You for all those who helped the solvers.
We usually measure angles in anti-clockwise direction.
So,the angle which is the major part in the rotation is measured as reflex angle,and mostly it is between 180 and 360 degrees.
Jasna said:
1 decade ago
The equation to find the angle between the hands is (11/2)*m-30h.
Where m:minutes.
h:hour reading.
Please explain the thing that in case of 3'oclock, that is 3.00.
The angle b/w hands are 90 degree, with the given equation it is got as 120 degree. How is it possible?. please explain how to use the equation properly, and where to use.
Where m:minutes.
h:hour reading.
Please explain the thing that in case of 3'oclock, that is 3.00.
The angle b/w hands are 90 degree, with the given equation it is got as 120 degree. How is it possible?. please explain how to use the equation properly, and where to use.
Pradip said:
8 years ago
@Madhuri.
We need to calculate total angle made by hour hand in 125/12 hours.
In 12 hours, hour hand cover 360 degrees.
Therefore for 1 hour = 360/12 degrees.
To calculate angle cover in 125/12 hours we multiply it with 360/12.
That is 360/12 * 125/12.
Which is similar to 30 * 125/12 { since hour hand cover 30 degrees in one hour}.
We need to calculate total angle made by hour hand in 125/12 hours.
In 12 hours, hour hand cover 360 degrees.
Therefore for 1 hour = 360/12 degrees.
To calculate angle cover in 125/12 hours we multiply it with 360/12.
That is 360/12 * 125/12.
Which is similar to 30 * 125/12 { since hour hand cover 30 degrees in one hour}.
Nikhila said:
1 decade ago
It can even be solved like this:
HOUR HAND:
For 1 hour, i.e., 60min angle covered by hour hand =360/12=30deg
For 25 min= (30*25/60) (cross multiply)= 12.5 deg.
Minute hand:
It goes from 10 and stops at 5 for 10.25
Therefore angle covered=(360*7/12)=210
Now subtact angle moved by minute hand from hour hand
210-12.5= 197.5 deg.
HOUR HAND:
For 1 hour, i.e., 60min angle covered by hour hand =360/12=30deg
For 25 min= (30*25/60) (cross multiply)= 12.5 deg.
Minute hand:
It goes from 10 and stops at 5 for 10.25
Therefore angle covered=(360*7/12)=210
Now subtact angle moved by minute hand from hour hand
210-12.5= 197.5 deg.
Mamun Rahaman said:
12 months ago
Reflex Angle Means an angle greater than 180 degrees but less than 360 degrees.
At 10 hr Angle = 30×10 = 300 degree.
For 25 min Angle= (25×5.5) = 162.5 degree (because 5.5 degree/min is the relative speed between min and hours hand)
Normal angle= (300-137.5) = 162.5 degree.
Therefore, Reflex Angle= 360-162.5= 197.5 degree.
At 10 hr Angle = 30×10 = 300 degree.
For 25 min Angle= (25×5.5) = 162.5 degree (because 5.5 degree/min is the relative speed between min and hours hand)
Normal angle= (300-137.5) = 162.5 degree.
Therefore, Reflex Angle= 360-162.5= 197.5 degree.
(36)
Bharat jee said:
1 decade ago
Hey friends,
Reflex angle simply means opposite angle, for solving this problem first of all we have to find out the angle made between 10:25. After than this angle is subtracted in 360.
Angle made b/w 10:25 == (360/12 x 10 + 25 x 1/2) - 25x6 = 325/2
Than reflexive angle == (360 - 325/2) = 395/2 = 197,1/2
So, Ans(D).
Reflex angle simply means opposite angle, for solving this problem first of all we have to find out the angle made between 10:25. After than this angle is subtracted in 360.
Angle made b/w 10:25 == (360/12 x 10 + 25 x 1/2) - 25x6 = 325/2
Than reflexive angle == (360 - 325/2) = 395/2 = 197,1/2
So, Ans(D).
Viraj said:
8 years ago
Formula:30(M/5-H)-M/2 if the minute hand is ahead of the hour hand.
30(H-M/5)+M/2 if the hour hand is ahead of the minute hand.
EXAMPLE: Angle for 4.15,
H=4 M=15.
Here we use the second formula because the value M/5 is less than the H.
= 30(H-M/5)+M/2,
= 30(4-15/5)+15/2,
= 75/2,
= 37.5.
30(H-M/5)+M/2 if the hour hand is ahead of the minute hand.
EXAMPLE: Angle for 4.15,
H=4 M=15.
Here we use the second formula because the value M/5 is less than the H.
= 30(H-M/5)+M/2,
= 30(4-15/5)+15/2,
= 75/2,
= 37.5.
Mahi said:
8 years ago
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.
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.
P.C. RAJASEKAR said:
1 decade ago
Hey thanks for everyone who gav the answer and who raised the questions. From you all I understood how to calculate angle between 2 hands and to calculate reflex angle.
Angle between 2 hands = 30(h) - (11/2)*m.
Reflex angle = 360 - angle between 2 hands.
(if angle between 2 hands is < 180).
Thanks to everyone.
Angle between 2 hands = 30(h) - (11/2)*m.
Reflex angle = 360 - angle between 2 hands.
(if angle between 2 hands is < 180).
Thanks to everyone.
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