Aptitude - Clock - Discussion
Discussion Forum : Clock - General Questions (Q.No. 15)
15.
At what time between 9 and 10 o'clock will the hands of a watch be together?
Answer: Option
Explanation:
To be together between 9 and 10 o'clock, the minute hand has to gain 45 min. spaces.
55 min. spaces gained in 60 min.
| 45 min. spaces are gained in |  |
60 | x 45 |  min or 49 |
1 | min. |
| 55 | 11 |
 The hands are together at 49 |
1 | min. past 9. |
| 11 |
Discussion:
48 comments Page 3 of 5.
Rossy said:
1 decade ago
Can someone please explain me, what is the main concept used to solve this problem?
Niraj kumar said:
1 decade ago
When the hands of watch together at that time it is obvious that angle made by hour's hand = angle made by minute's hand.
Let us assume both hand meet at time (9+x/60), where x = minute.
Now, (9+x/60)*360/12=x*360/60 (angle made by both hand).
After solving this equation, we find x=540/11. So ans=9hr, 540/11min. i.e = Option C.
Let us assume both hand meet at time (9+x/60), where x = minute.
Now, (9+x/60)*360/12=x*360/60 (angle made by both hand).
After solving this equation, we find x=540/11. So ans=9hr, 540/11min. i.e = Option C.
(2)
Chandresh said:
1 decade ago
You can try this way also.
360 = 30(10)-(11/2)m.
360-300 = (11/2)m.
(60*2)/11 = m.
m = 120/11;
Now just do: 60-(120/11) = 540/11 = 49.1/11.
360 = 30(10)-(11/2)m.
360-300 = (11/2)m.
(60*2)/11 = m.
m = 120/11;
Now just do: 60-(120/11) = 540/11 = 49.1/11.
A k singh said:
1 decade ago
What master formula you are giving its not applicable to a single question we are doing. All the time its having negative sign error. I don't think so that is the master formula but can say this is confusing the whole concept we read till now.
Jeet said:
1 decade ago
In Q6 at 7, they are 25 mins apart, but in this Q at 9 they are 45 mins apart, is the angle measured clockwise/ anti clockwise?
Aarthi said:
1 decade ago
Can you tell me the correct explanation?
Abhishek said:
1 decade ago
@Kapil.
Awesome man done in the most basic way manner as possible. Really appreciate your work.
Awesome man done in the most basic way manner as possible. Really appreciate your work.
Smita said:
10 years ago
Past 9n means?
Sonam said:
10 years ago
When asking will the hands of a watch be together?
Use (60/11)h.
= 60*9/11.
= 540/11.
= 49 1/11.
Use (60/11)h.
= 60*9/11.
= 540/11.
= 49 1/11.
Bhavesh Kirange said:
10 years ago
I don't understand the concept here you are assuming. In question from 9 to 10 o'clock the hands should be meet each other on 9.50 o'clock in real situation by watch.
But how could you say here they are meeting on 9.45 o'clock means we are suppose to assume hour hand at stable position?
But how could you say here they are meeting on 9.45 o'clock means we are suppose to assume hour hand at stable position?
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