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?
45 min. past 9
50 min. past 9
49 1 min. past 9
11
48 2 min. past 9
11
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:
47 comments Page 5 of 5.

Krishnadas said:   1 decade ago
@sree. Good work. But is this formula standard?

Shree Hema said:   1 decade ago
@manish
better use this formula
theta=11(m)/2-30(h)
if both hands coincide degree ll be 0
if both hands r in opposite direction degree will be 180
if both hands r in right angle degree will be 90
here it coincides so 0 degree
we have to find min only so keep that parameter(m) as it is, use minimum hour for hour parameter(h=9)
0=11(m)/2-30(9)
m=49 1/11
Got It???

Manish said:   1 decade ago
I don't understand this method please explain it. Why we take 55 min ?

Vipin said:   1 decade ago
Alternative method::

Let the minutes covered when d situation occurs = x
now,
(total degrees covered by minute hand) - (total degrees covered by hr hand)= (outer angle between 12 and 9) i.e.
6x - x/2 = 270

x=540/11 which is our ans. :)

Krish said:   1 decade ago
Sakshi,

The question is between 9 and 10 both the hands must coincide,.

So for the minute hand to reach 9 it has to gain 45 minute spaces.

Yamini said:   1 decade ago
Why you take the 55 min spaces ?

Sakshi said:   1 decade ago
How do we know that min? Hand has to gain 45 mins?


Post your comments here:

Your comments will be displayed after verification.