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.
Swathi sayyapureddy said:
6 years ago
@Shree.
When hour hand is preceding minute hand then theta=30H~11M/2 will be used otherwise, means when min hand is preceding hour hand then theta=11M/2~30H can be used.
When hour hand is preceding minute hand then theta=30H~11M/2 will be used otherwise, means when min hand is preceding hour hand then theta=11M/2~30H can be used.
(4)
Dipankar Mondal said:
6 years ago
40 * 12/11 = 43 7/11.
(3)
Sonam said:
7 years ago
Can you explain me the calculation of 43 7/11 min how it comes from (60/55*40) min?
(1)
Ragav said:
7 years ago
Why we can't use 30H - 5.5H = 90 formula?
30(11/2) - 5.5H = 90.
30(11/2) - 5.5H = 90.
(1)
Saidul said:
7 years ago
Thanks @Harry.
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?
Saravana said:
8 years ago
How the calculation (60\55)*40 = 43*7/11?
Vijaya said:
8 years ago
I don't understand how, 15 m gain? please anyone explain it.
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)
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)
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