Aptitude - Clock - Discussion
Discussion Forum : Clock - General Questions (Q.No. 14)
14.
At what time between 4 and 5 o'clock will the hands of a watch point in opposite directions?
Answer: Option
Explanation:
At 4 o'clock, the hands of the watch are 20 min. spaces apart.
To be in opposite directions, they must be 30 min. spaces apart.
Minute hand will have to gain 50 min. spaces.
55 min. spaces are gained in 60 min.
| 50 min. spaces are gained in |  |
60 | x 50 |  min. or 54 |
6 | min. |
| 55 | 11 |
| Required time = 54 |
6 | min. past 4. |
| 11 |
Discussion:
55 comments Page 4 of 6.
Srikanth said:
1 decade ago
Here 30 min space apart means for opposite directions of minute hand and hour hand 30 min space apart.
Shree Hema said:
1 decade ago
Here we can use the formula:
theta=11(m)/2-30(h)
opposite direction means 180 degree; hour=4
180=11(m)/2-30(4)
m=54 6/11
theta=11(m)/2-30(h)
opposite direction means 180 degree; hour=4
180=11(m)/2-30(4)
m=54 6/11
Shivakarthik said:
1 decade ago
Its simple only so i think formula s no need for this ... if both the hands r in opposite direction or in the same straight line in 30 mins spaces ... v have 2 find out the time b\w 4 to 5 . at the time of 4 the spaces b\w the both hand s 20 min so 20=30=50 ...
60/55*50 =54*6/11min past4. hope u will understand?
60/55*50 =54*6/11min past4. hope u will understand?
Shivakarthik said:
1 decade ago
Its simple only so i think formula s no need for this ... if both the hands r in opposite direction or in the same straight line in 30 mins spaces ... v have 2 find out the time b\w 4 to 5 . at the time of 4 the spaces b\w the both hand s 20 min so 20+30=50 ...
60/55*50 =54*6/11min past4. hope u will understand?
60/55*50 =54*6/11min past4. hope u will understand?
Neeraj said:
1 decade ago
Why 50 min why not 10 min to be 30 spaces apart ?
Xyz said:
1 decade ago
Can somebody tell me why it will gain only 55 min spaces in 60 min?
Xyz said:
1 decade ago
@Neeraj
Because the minutes hand can move only in clock-wise direction. So 20 min to reach at the same place as the hour hand + 30 min reach in the opposite direction.
Because the minutes hand can move only in clock-wise direction. So 20 min to reach at the same place as the hour hand + 30 min reach in the opposite direction.
Abc said:
1 decade ago
Same query as xyz have. Please answer it if any one knows.
Aravind said:
1 decade ago
@xyz can you explain that 20+30 again?
Ranjit said:
1 decade ago
Assume that they are in opposite directions after x mins..
Then minute hand has traveled x mins...
The hour hand has traveled (x*5)/60 mins from the 4 o' clock position. To this add 20 min to give (x/12)+20 min as its displacement from 12 o' clock...
Now the difference between their positions is 30 mins..
So solve x-((x/12)+20)=30.
Then minute hand has traveled x mins...
The hour hand has traveled (x*5)/60 mins from the 4 o' clock position. To this add 20 min to give (x/12)+20 min as its displacement from 12 o' clock...
Now the difference between their positions is 30 mins..
So solve x-((x/12)+20)=30.
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