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 3 of 8.
Tilak Dewangan said:
9 years ago
Sorry @Riddilavan your formula may wrong if you solve this question.
How many minutes after 7 o'clock and before 8'o clock will the hands of the clock be in opposite direction?
How many minutes after 7 o'clock and before 8'o clock will the hands of the clock be in opposite direction?
Krish said:
1 decade ago
I have the same doubt as @Margaret said. Please anyone explain it.
Abc said:
10 years ago
Superb formula. Thanks alot.
Prithvi said:
9 years ago
Thanks @Harry.
Kumar said:
9 years ago
Since for 1 hour, the minute's arm move 360 degrees. And for each hour arm move 30 degrees.
Hence for every 1 degree move the minute's arm move 12 degrees.
When the time is 5 : 30 the angle between the min arm and hour arm is 15 degree.
Our target to find a time when the angle is 90 degree.
For this, we solve the equation :12x - x + 15 = 90.
From here we get x = 75/11.
30 degree = 1 hour.
75/11 degree = 1/30 * 75/11 = 5/22hours = 300/22min.
Hence final time is 30 + 300/22 = 480/22 min from 5 o'clock. (we add 30 because we have considered the arms move from 5:30).
Hence for every 1 degree move the minute's arm move 12 degrees.
When the time is 5 : 30 the angle between the min arm and hour arm is 15 degree.
Our target to find a time when the angle is 90 degree.
For this, we solve the equation :12x - x + 15 = 90.
From here we get x = 75/11.
30 degree = 1 hour.
75/11 degree = 1/30 * 75/11 = 5/22hours = 300/22min.
Hence final time is 30 + 300/22 = 480/22 min from 5 o'clock. (we add 30 because we have considered the arms move from 5:30).
Nagu said:
10 years ago
Why the spaces are same for 5'clock and 7'clock == 25 spaces?
In which direction we have to take the spaces clock wise or anti clock wise?
In which direction we have to take the spaces clock wise or anti clock wise?
Jonas palmiano said:
1 decade ago
What time after 4 o'clock will the hands of the clock be at right angle? Please help.
Mounika said:
9 years ago
I was getting confused in using the formula.
But your answer helps me, Thankyou @Prashanth.
But your answer helps me, Thankyou @Prashanth.
Yuvrajsinh said:
9 years ago
Friends please help me, I don't know this chapter.
Ashu said:
8 years ago
How can you get 11/2 in the formula?
Can anyone help me? Please.
Can anyone help me? Please.
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