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?
5 min. past 7
5 2 min. past 7
11
5 3 min. past 7
11
5 5 min. past 7
11
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:
71 comments Page 5 of 8.

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

Marati Raju said:   1 decade ago
This problem is very simple . . . .
For this problem
in clock 7 ki opposite 1 i.e 5min
hence at 5:[5/11]min past 7 O'clock at that time hands of a clock be in straight line
or
at 60/11 min past 7
the hands of a clock on straight line . . . . .

Puja ahirwal said:   1 decade ago
Please tell me about when minute space are add or subtract.

Rakesh said:   1 decade ago
Can some one give me a simple way to solve these watch question ?

Pritam said:   1 decade ago
How 55 min. spaces are gained in 60 min?

Can anybody explain?

Rajesh said:   1 decade ago
This type of problem
remember these formula:
(5x+30)12/11 where x<6
(5x-30)12/11 where x>6

In this problem 7 and 8 clock
So here 7 is grater than 6(x>6)
So we use this formula :(5x-30)12/11 where x>6
Here x=7 so :(5x7-30)12/11= 60/11=5+5/11
So the answer is: (5+5/11) minute and 7 past.

Scientist said:   2 decades ago
Dear aparna how did you got 11/2 ?

Vivek jain said:   2 decades ago
How 55 min. spaces are gained in 60 min. ?

Please somebody tell me!

Harshad said:   2 decades ago
How do you know that at 7 the difference is 25min?

@ Nitesh: Assuming I don't have a watch to look at and count the minutes.

Fatima said:   2 decades ago
Please someone clear that what angle in 8o'clock9 between.


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