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 4 of 7.
John said:
7 years ago
@Vivek Jain.
In 1 hr minute, min hand covers 60 min and hr hand covers 5 min. Comparing both minute hand gains 55 min in 1 hr.
In 1 hr minute, min hand covers 60 min and hr hand covers 5 min. Comparing both minute hand gains 55 min in 1 hr.
Bhushan suriya said:
7 years ago
(210-6a)+(30/60)a = 180.
I think this will be the perfect solution.
I think this will be the perfect solution.
Riya shah said:
9 years ago
Shortcut formula:
ANGLE = 30*H - 11/2M.
Together Means angle consider as zero.
Put into the formula.
0 = 30 * 7 - 11/2M.
11/2M = 210.
Imp together consider as zero.
ANGLE = 30*H - 11/2M.
Together Means angle consider as zero.
Put into the formula.
0 = 30 * 7 - 11/2M.
11/2M = 210.
Imp together consider as zero.
Bhargav Bhatti said:
9 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.
Ajeesh R Nair said:
5 years ago
@Himanshu
How min hand increases angle? Please explain.
How min hand increases angle? Please explain.
Faiz said:
1 decade ago
@Harshad
Man at 7 o clock, the hour hand is at 7 and the minute hand is in 12 i.e 60th min. assume the display in your watch is like 5 10 15.. 60.. so at 7 the hour hand will be at 35 and the min hand will be in 60.. now jus go on adding the minute space clockwise or els simple (60-35) gives 25 mins space..!!
Man at 7 o clock, the hour hand is at 7 and the minute hand is in 12 i.e 60th min. assume the display in your watch is like 5 10 15.. 60.. so at 7 the hour hand will be at 35 and the min hand will be in 60.. now jus go on adding the minute space clockwise or els simple (60-35) gives 25 mins space..!!
Himanshu dewaangan said:
1 decade ago
ANOTHER METHOD:
In 7 o'clock there are angle between hands= 5*30=150 degree
we have to make that angle = 180 degree
let after X min
min hand will increase angle by = X*6 =6X,on 150 degree
1 degree of min = 1/12 degree of hr
6X degree of min = 6X/12 = X/2 degree of hr (decrease angle on 150)
so angle have to be between hands=180
150+6X-X/2=180
x=5+5/11
ANS=(5+5/11) minute and 7 past
In 7 o'clock there are angle between hands= 5*30=150 degree
we have to make that angle = 180 degree
let after X min
min hand will increase angle by = X*6 =6X,on 150 degree
1 degree of min = 1/12 degree of hr
6X degree of min = 6X/12 = X/2 degree of hr (decrease angle on 150)
so angle have to be between hands=180
150+6X-X/2=180
x=5+5/11
ANS=(5+5/11) minute and 7 past
SHEKHAR said:
1 decade ago
@amit:11/2min-30h this formula applicable only when h<6
if u put h=6 or above then the min>60 which is not acceptable(for the 180 degree),
in this problem if we put that formula then the ans is 77(10/11)
but in that case the h=7 so we apply the another formula which is 30h-11/2
in this case if we put that then formula the ans is 5(5/11)
if u apply that formula then u will find that min<60 which is acceptable
BASICALLY WE NEED THIS 2 FORMULAS BUT IN DIFF CASE...
hope u will understand:)
if u put h=6 or above then the min>60 which is not acceptable(for the 180 degree),
in this problem if we put that formula then the ans is 77(10/11)
but in that case the h=7 so we apply the another formula which is 30h-11/2
in this case if we put that then formula the ans is 5(5/11)
if u apply that formula then u will find that min<60 which is acceptable
BASICALLY WE NEED THIS 2 FORMULAS BUT IN DIFF CASE...
hope u will understand:)
Amit said:
1 decade ago
What is the formula? whether its 11/2*min-30hr or 30hr-11/2*min?
Rajendra Sahu said:
1 decade ago
For straight line angle =180
The formula is for finding angle =30H-(11/2)*M
where H =>Hours
M => Minute.
Now
30H-(11/2)*M=180
30*7-(11/2)*M=180
210 - (11/2)*M=180
-(11/2)*M=180-210
-(11/2)*M=-30
11*M=60 (Cross Multiply)
M=60/11 minutes
means 5+5/11 minute
So Time will be
(5+5/11) minute and 7 past
The formula is for finding angle =30H-(11/2)*M
where H =>Hours
M => Minute.
Now
30H-(11/2)*M=180
30*7-(11/2)*M=180
210 - (11/2)*M=180
-(11/2)*M=180-210
-(11/2)*M=-30
11*M=60 (Cross Multiply)
M=60/11 minutes
means 5+5/11 minute
So Time will be
(5+5/11) minute and 7 past
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers