Hi guys..can anyone explain me this:
A certain clocks marks every hour by striking a number of times equal to the hour, and the time required for a stroke is exactly equal to the time interval between strokes.At 6:00 the time lapse between the beginning of the first stroke and the end of the last stroke is 22 seconds.At 12:00 ,how many seconds elapse between the beginning of the first stroke and the end of the last stroke?
a.72
b.50
c.48
d.46
e.44
thanks.
Gmat review question
This topic has expert replies
OA is D = 46
In explanation :
At 6 there were 6 strokes and 5 intervals between each stroke.
Lets say clock strikes like : tum (just a sound )
So at 6 it will be :
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum
which is total of 6 tum and 5 interval.
Question says - time required for a stroke is exactly equal to the time interval between strokes.
So tum = interval
That is, we have 11 equal time intervals that took 22 seconds.
1 tum or interval = 2 seconds
Therefore at 12 : 12 tum and 11 interval = (2*12) + (2*11) = 24+ 22 = 46
I hope this helps..
In explanation :
At 6 there were 6 strokes and 5 intervals between each stroke.
Lets say clock strikes like : tum (just a sound )
So at 6 it will be :
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum
which is total of 6 tum and 5 interval.
Question says - time required for a stroke is exactly equal to the time interval between strokes.
So tum = interval
That is, we have 11 equal time intervals that took 22 seconds.
1 tum or interval = 2 seconds
Therefore at 12 : 12 tum and 11 interval = (2*12) + (2*11) = 24+ 22 = 46
I hope this helps..
Hi onesome,
Thanks a ton.. but as u said..
Question says - time required for a stroke is exactly equal to the time interval between strokes.
So tum = interval
That is, we have 11 equal time intervals that took 22 seconds.
1 tum or interval = 2 seconds
Therefore at 12 : 12 tum and 11 interval = (2*12) + (2*11) = 24+ 22 = 46
CAn u please explain me..as to how 11 intervals in 12 seconds.. and how 1 interval=2 seconds..i am just not getting that...
thanks..
Thanks a ton.. but as u said..
Question says - time required for a stroke is exactly equal to the time interval between strokes.
So tum = interval
That is, we have 11 equal time intervals that took 22 seconds.
1 tum or interval = 2 seconds
Therefore at 12 : 12 tum and 11 interval = (2*12) + (2*11) = 24+ 22 = 46
CAn u please explain me..as to how 11 intervals in 12 seconds.. and how 1 interval=2 seconds..i am just not getting that...
thanks..
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Hi Raunekk,
I just want to help to make it clear for you... you asked:
CAn u please explain me..as to how 11 intervals in 12 seconds.. and how 1 interval=2 seconds..i am just not getting that...
It was not 11 intervals in 12 seconds, but it is total 11 periods of "tums" and intervals. It is exactly like Onesome analogy :
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum
from the analogy above we can see that at 6.00 there are 6 tums + 5 intervals = 11 periods of time. And 11 periods of time needs 22 seconds. Right?
So, we can simply find the time needed for 1 period, 22 seconds / 11 periods = 2 second / period.
Now, by the same analogy, if it is 12.00, so we will hear the tum 12 times right. So the analogy is:
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum
We have 12 tums and 11 intervals --> 12 + 11 = 23 periods, right?
1 period needs 2 seconds, so in 23 periods we need exactly 23 periods x 2 seconds = 46 seconds (D)
I hope this helps...
Enjoy your day
I just want to help to make it clear for you... you asked:
CAn u please explain me..as to how 11 intervals in 12 seconds.. and how 1 interval=2 seconds..i am just not getting that...
It was not 11 intervals in 12 seconds, but it is total 11 periods of "tums" and intervals. It is exactly like Onesome analogy :
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum
from the analogy above we can see that at 6.00 there are 6 tums + 5 intervals = 11 periods of time. And 11 periods of time needs 22 seconds. Right?
So, we can simply find the time needed for 1 period, 22 seconds / 11 periods = 2 second / period.
Now, by the same analogy, if it is 12.00, so we will hear the tum 12 times right. So the analogy is:
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum <interval>
tum
We have 12 tums and 11 intervals --> 12 + 11 = 23 periods, right?
1 period needs 2 seconds, so in 23 periods we need exactly 23 periods x 2 seconds = 46 seconds (D)
I hope this helps...
Enjoy your day
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