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 1 of 7.
Swaraj said:
2 months ago
The angle required is 180°.
At 7 the angle would be 25×6°=150°
So let's assume it moves x mins after 7.
So, keeping the movement of the hour hand and minute hand during these x mins, we can write the angle between both the hands as;
180°=150°+ (X. 6°- X. 1/2°).
=>30°=X(5.5) =>X=30°/5.5=5 5/11mins(Ans).
At 7 the angle would be 25×6°=150°
So let's assume it moves x mins after 7.
So, keeping the movement of the hour hand and minute hand during these x mins, we can write the angle between both the hands as;
180°=150°+ (X. 6°- X. 1/2°).
=>30°=X(5.5) =>X=30°/5.5=5 5/11mins(Ans).
(1)
Bhargav Bhatti said:
4 months ago
@All.
As we know that;
1hr i.e. 60 min the the minute hand gains 55 minute spaces over the hour hand.
So in the minute formula just replace 60 by 55 to get the answer
Given:-
The min and hour hand are in a straight line so the angle between them is 180 degrees
So angle = 180 degree.
Formula :
= |55x7-360/11|,
= 385 - 360/11 = 25/11.
Hence, the answer = 5 5/11.
As we know that;
1hr i.e. 60 min the the minute hand gains 55 minute spaces over the hour hand.
So in the minute formula just replace 60 by 55 to get the answer
Given:-
The min and hour hand are in a straight line so the angle between them is 180 degrees
So angle = 180 degree.
Formula :
= |55x7-360/11|,
= 385 - 360/11 = 25/11.
Hence, the answer = 5 5/11.
Nanthakumar said:
11 months ago
Simple method.
55 = 60.
Then 5 = x.
55x= 300.
x=300/55.
x= 5 5/11.
55 = 60.
Then 5 = x.
55x= 300.
x=300/55.
x= 5 5/11.
(2)
Rohit Joshi said:
1 year ago
As the clocks are in a straight line but not together, the angle formed by the hands of the clock will be 180.
Now, We know that Angle = |30*Hours - 11/2*Minutes|
Therefore, 180 = 30*7 * 11/2 * Minutes.
210 - 180 = 11/2 * Minutes.
30 = 11/2 * Minutes.
60/11 = Minutes.
55 * 5/11 = Minutes.
So, finally, the answer is D.
Now, We know that Angle = |30*Hours - 11/2*Minutes|
Therefore, 180 = 30*7 * 11/2 * Minutes.
210 - 180 = 11/2 * Minutes.
30 = 11/2 * Minutes.
60/11 = Minutes.
55 * 5/11 = Minutes.
So, finally, the answer is D.
(16)
Tushar said:
2 years ago
To calculate the angle between hr hand and min hand.
we have formula ->> 30*Hours-11/2*minutes.
In the above question, they said that minute and hour hands are in one line but not together means Angel between them should be 180°.
:: 30 * 7 - 11/2 * x = 180°.
Then, x = 5.4545 ~5 + 5/11.
we have formula ->> 30*Hours-11/2*minutes.
In the above question, they said that minute and hour hands are in one line but not together means Angel between them should be 180°.
:: 30 * 7 - 11/2 * x = 180°.
Then, x = 5.4545 ~5 + 5/11.
(32)
Mohit Sharma said:
4 years ago
θ = { hour * 30 } diff { min * 11/2 } take difference between greater value and smaller value.
Now for the straight line, we know θ = 180.
We can put all these values in the formula
Hour = 7
θ = 180
min = ?
θ = hour * 30 diff min * 11/2.
180 = { 7 * 30 } diff { min* 11/2}.
180 = { 210 } diff { min* 11/2},
min = 2/11 * 210-180,
min = 60/11.
which is equal to 5 5/11.
Now for the straight line, we know θ = 180.
We can put all these values in the formula
Hour = 7
θ = 180
min = ?
θ = hour * 30 diff min * 11/2.
180 = { 7 * 30 } diff { min* 11/2}.
180 = { 210 } diff { min* 11/2},
min = 2/11 * 210-180,
min = 60/11.
which is equal to 5 5/11.
(4)
Ashwini said:
4 years ago
60/55 I don't get this step. Please anyone explain.
(3)
Bangya said:
4 years ago
Assume that the time is 1 O'clock. If we look in a clockwise direction, it's 55 min space but if we look in the anticlockwise direction, it's 5-minute space. Can somebody explain which direction should we look to know the correct minute space?
If both directions are correct, then 5-minute space will be equal to 55-minute space.
If both directions are correct, then 5-minute space will be equal to 55-minute space.
(1)
Santhoshi vempati said:
5 years ago
The angle between minute's hand hour's hand=30H-(11/2)M.
H = hours; M = minutes.
Given hour's and minute's is a straight line, so the angle is 180degrees.
180 = 30(7) - (11/2) * M,
M = 60/7 = 5 5/11,
So, the answer is 5 5/11min.past 7.
H = hours; M = minutes.
Given hour's and minute's is a straight line, so the angle is 180degrees.
180 = 30(7) - (11/2) * M,
M = 60/7 = 5 5/11,
So, the answer is 5 5/11min.past 7.
(8)
Ajeesh R Nair said:
5 years ago
@Himanshu
How min hand increases angle? Please explain.
How min hand increases angle? Please explain.
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