Aptitude - Clock - Discussion
Discussion Forum : Clock - General Questions (Q.No. 6)
6.
At what time between 7 and 8 o'clock will the hands of a clock be in the same straight line but, not together?
Answer: Option
Explanation:
When the hands of the clock are in the same straight line but not together, they are 30 minute spaces apart.
At 7 o'clock, they are 25 min. spaces apart.
Minute hand will have to gain only 5 min. spaces.
55 min. spaces are gained in 60 min.
| 5 min. spaces are gained in |  |
60 | x 5 |  min |
= 5 | 5 | min. |
| 55 | 11 |
| Required time = 5 |
5 | min. past 7. |
| 11 |
Discussion:
70 comments Page 6 of 7.
Aparna said:
1 decade ago
Simple method:
In one hour,once minute hand and hour hand comes in straight line
so our answer is something 7 past,not 8 past
use formula,
titha(0)=30h-11/2m
titha is 180,hour hand is on 7
put values
we get titha=60/11
convert into quotitent*remainder/divisor format
we get
5*5/11
So answer is 5*5/11 past 7.
In one hour,once minute hand and hour hand comes in straight line
so our answer is something 7 past,not 8 past
use formula,
titha(0)=30h-11/2m
titha is 180,hour hand is on 7
put values
we get titha=60/11
convert into quotitent*remainder/divisor format
we get
5*5/11
So answer is 5*5/11 past 7.
Gopal said:
1 decade ago
I think they are counting clock wise direction from hour hand to minute hand. If they count from minute hand to hour hand it will be 35 mins
Nitesh Nandwana said:
1 decade ago
@Nithya.
This is very simple just see clock at the time of 7 o'clock.
The difference between hour hand and minute is 25 min.
This is very simple just see clock at the time of 7 o'clock.
The difference between hour hand and minute is 25 min.
Hari said:
1 decade ago
See from clock 3.
At 1 o'clock they are 55 min spaces apart.
2 o'clock......50 min......
3....... 45 min.......
4....... 40 min.......
.
.
.
7........ 25 min......
At 1 o'clock they are 55 min spaces apart.
2 o'clock......50 min......
3....... 45 min.......
4....... 40 min.......
.
.
.
7........ 25 min......
Riya said:
9 years ago
Not together so angle 180.
Angle = 30 * H + 11/2 * M.
Angle = 30 * H + 11/2 * M.
Harish udupa s said:
9 years ago
Angle = |11/2 * min-30 * hr| as said by someone.
Where || indicates take positive value.
How is this derived?
=> For every hour, hour hand rotates by 30 degrees (360/12 = 30).
=> For every minute, minute hand rotates by 6 degrees (360/60 = 6).
=> But for every minute, hour hand rotates by 1/2 degree (1 hr = 30 degrees 1 min = half degree).
=> So effective angle = (6 * min) - ((30 * hr) + (0.5 * min)).
=> Solving angle = 5.5 * min - 30 * hour.
Where || indicates take positive value.
How is this derived?
=> For every hour, hour hand rotates by 30 degrees (360/12 = 30).
=> For every minute, minute hand rotates by 6 degrees (360/60 = 6).
=> But for every minute, hour hand rotates by 1/2 degree (1 hr = 30 degrees 1 min = half degree).
=> So effective angle = (6 * min) - ((30 * hr) + (0.5 * min)).
=> Solving angle = 5.5 * min - 30 * hour.
Paddu said:
9 years ago
Hello friends please explain in shortcut. I am still in confused.
Vash said:
10 years ago
Let x = to minutes and x/12 = to hour.
x = 35+x/12-30 = 12x = 420+x-360.
11x = 60. 35 minutes = 7 o'clock.
I put -30 because x = 60/11 directly opposite to each other = 5.45 or 5 5/11.
180 degrees.
x = 35+x/12-30 = 12x = 420+x-360.
11x = 60. 35 minutes = 7 o'clock.
I put -30 because x = 60/11 directly opposite to each other = 5.45 or 5 5/11.
180 degrees.
Renz said:
10 years ago
Hai, what is the basic steps or formula in solving problems?
Jainish said:
10 years ago
Hi, Can anyone explain me how will get 5 5/11 answer, I got method buy I didn't get after 60/55*5 how it will get 5 5/11 answer?
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