Aptitude - Clock - Discussion
Discussion Forum : Clock - General Questions (Q.No. 7)
7.
At what time between 5.30 and 6 will the hands of a clock be at right angles?
Answer: Option
Explanation:
At 5 o'clock, the hands are 25 min. spaces apart.
To be at right angles and that too between 5.30 and 6, the minute hand has to gain (25 + 15) = 40 min. spaces.
55 min. spaces are gained in 60 min.
| 40 min. spaces are gained in |  |
60 | x 40 |  min |
= | 43 | 7 | min. |
| 55 | 11 |
 Required time = 43 |
7 | min. past 5. |
| 11 |
Discussion:
76 comments Page 2 of 8.
Ankita said:
5 years ago
@Abi and @ Babu.
When two hands coincide after exactly one hour, minutes hand travels one full circle that is 60 spaces but hours hand moves 5 space forward. So after exactly one hour later, they gain 55 spaces are their relative gain.
When two hands coincide after exactly one hour, minutes hand travels one full circle that is 60 spaces but hours hand moves 5 space forward. So after exactly one hour later, they gain 55 spaces are their relative gain.
(2)
Jack84 said:
8 years ago
@ALL.
Min=AO
Hour=OB
AOB=25 min apart
To get 90 degree= minutes has to travel another 15 min from 5 O'clock i.e. 5:40 so, 25+15=40 min.
OB i.e.hour hand travels only 5 min in 60 min so=60-5=55 min,
the rest is given by experts.
Min=AO
Hour=OB
AOB=25 min apart
To get 90 degree= minutes has to travel another 15 min from 5 O'clock i.e. 5:40 so, 25+15=40 min.
OB i.e.hour hand travels only 5 min in 60 min so=60-5=55 min,
the rest is given by experts.
(1)
Abhiram said:
1 decade ago
@Akki, The given question is hands must be in right angles so 90 degrees is taken.
@Shree, You can take any f the formula but take care not to get a -ve theta if it comes -ve then take another formula ts as simple as such.
@Shree, You can take any f the formula but take care not to get a -ve theta if it comes -ve then take another formula ts as simple as such.
Vaibhav patil jadhav said:
1 decade ago
@Priya.
We can't write 5:30 as (5+1/2)hrs bcoz it is written 5 hrs from 5 to 6 o'clock....we automatically find the minutes where they both meet using the formula theta = 11/2(min)-30(hrs) as the angle is less than 180.
We can't write 5:30 as (5+1/2)hrs bcoz it is written 5 hrs from 5 to 6 o'clock....we automatically find the minutes where they both meet using the formula theta = 11/2(min)-30(hrs) as the angle is less than 180.
A. M. said:
8 years ago
The given explanation doesn't consider the movement of the hour hand. Between 5:30 and 6, the hour hand will also have moved. Then the minute hand will need to cover a little more than (25 + 15) minutes' space.
(1)
Susmitha said:
1 decade ago
In 1 hour a minute hand covers 60 minute divisions (minute spaces) where as an hour hand covers only 5 minute divisions in 1 hour. Thus minute hand gains 55 (i. e;60-5) minute divisions in 60 minutes (1 hour).
Vaibhav patil jadhav said:
1 decade ago
Hi guys,
Here either of the formulas can be applied but the thing is the angle must not be negative you definitely gets the answer.
Theta = 11/2(min)-30(hrs)...or theta = 30(hrs)-11/2(min).
Good luck.
Here either of the formulas can be applied but the thing is the angle must not be negative you definitely gets the answer.
Theta = 11/2(min)-30(hrs)...or theta = 30(hrs)-11/2(min).
Good luck.
Amjad said:
4 months ago
@All
| 5.5X - 5*30 | = 90.
5.5X - 5 * 30 = +90 and 5.5X - 5 * 30 = -90.
By solving this we will get both the answers where at 5'o clock at which they make 90deg angle.
Hope this helps!
| 5.5X - 5*30 | = 90.
5.5X - 5 * 30 = +90 and 5.5X - 5 * 30 = -90.
By solving this we will get both the answers where at 5'o clock at which they make 90deg angle.
Hope this helps!
(5)
Siddharth Pandey said:
7 years ago
Tell me both the times at which der will be 90-degree b/w min hand and second hand between 1 AM/PM to 2 AM/PM using the formula mentioned above. Does this formula work for given timings?
Prasad said:
1 decade ago
@Reddilavan
The formula you provided is Master formula. It works on almost all kind of problems of clock to find angle between the clock hands. Just take care of angle while choosing.
The formula you provided is Master formula. It works on almost all kind of problems of clock to find angle between the clock hands. Just take care of angle while choosing.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers