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Between 12:24 and 14:36 the hour hand of the clock turns by [#permalink]
 28 Oct 2008, 06:23
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Question Stats:
64% (01:35) correct
35% (00:45) wrong based on 84 sessions
Between 12:24 and 14:36 the hour hand of the clock turns by (A) 60 degrees (B) 66 degrees (C) 72 degrees (D) 74 degrees (E) 76 degrees Source: GMAT Club Tests - hardest GMAT questions
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bigfernhead wrote: Between 12:24 and 14:36 the hour hand of the clock turns by
60 degrees
66 degrees
72 degrees
74 degrees
76 degrees ~66 degrees At 12:24 hour hand will be at 2 * 6 = 12 degrees from 12. After 18 degrees it will reach 13:00 (3 divisions remaining so 3*6 degrees) After 30 degrees it will reach 14:00 ( 5 divisions 5*6) After 18 degrees it will reach 14:36 ( 3 divisions 3*6) Thus hour hand will turn by 18 + 30 + 18 = 66 degrees
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I agree with the 66 degrees answer. First, there is 360 degrees movement every 12 hours. 360 / 12 = 30 degrees between each number, which the hour hand moves in 60 minutes. So in 1 minute, the hour hand moves one half degree. Now that we know how far the hour hand moves per minute, we can figure out how many minutes there are between 12:24 and 14:36. That would be 2 hours 12 minutes, or 132 minutes. 132 * 1/2 = 66. bigfernhead wrote: Between 12:24 and 14:36 the hour hand of the clock turns by
60 degrees
66 degrees
72 degrees
74 degrees
76 degrees
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66 degrees seems to be the right answer. Angular distance traveled = Angular speed <degrees traveled /minute> * Time <minutes>. Which in this case will be 0.5 deg/min * 132 = 66 degrees.
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Ans: B in 1 hour 30 DEG. & 1/2 DEG in min. so in 2 hour 12 min 66 DEG
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12:24 - 14:24 = 120mins 14:24 - 14:36 = 12mins total time = 2 hrs 12mins 12 hours = 360 degrees 1 hr = 30 deg 2 hrs = 60 degrees 12mins = 12/60 * 30 = 6 degrees Angular distance covered = 66 degrees
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total min = 132 So hour hand moved 132 * (1/2) degree = 66 66 is the snswer.
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Okay once again before peeking. The first thing is to figure how many degrees each hour segment is. This is easy. 12 hours and 360 degrees. One twelfth of 360=30 degrees. Then how much for minutes. 60 minutes = 30 degrees.
Next the difference between the two times is 2 hours (30x2=60 degrees) and 12 minutes. So we want to see how any degrees in 12 minutes. 12/60 = 1/5. we multiply this by 30 degrees and get 6 degrees.
So very quickly we see the answer is 66 degrees. Answer B.
Now peeking. B. Yay!
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In 12 * 60 min, hour hand turns by 360 degrees 12:24 - 14:36 = 2 hrs 12 min = 120 + 12 = 132 min => Angles turned = 360/720 * 132 degrees = 132/2 = 66 degrees Answer - B
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66 degrees. Pretty easy to logic this one out.
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In one hour, the hour hand moves 360/12 = 30 degree. so from 12:24 to 14:24 it will move 30 + 30 = 60 degrees. now from 14:24 to 14:36 the total time passed is 12 minutes which is 1/5 of one hour so the hour hand will move 1/5 of what it moves in one hour i.e. 30/5 = 6 so the total angle the hour hand has moved is 30+30+6 = 66 degrees. hence answer is B
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12 hr = 360 degree rotation => 1 hour =30 degree rotation =>2.2 hours =66 degree rotation Answer is B. Posted from my mobile device 
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Hi there, I can't figure out what's wrong..but..
I understand 360 degrees/ 12 hour = 30 degrees per hour..
but 360 degree/60min = 6 degree per min...
why 1/2??
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Ans: 66 Deg
12 Hrs --> 360 Deg
1 Hr --> (360/12) --> 30 Deg
1 min --> 30/60 --> 0.5 Deg
12:24 to 14:36 = 2 hrs 12 mins => (30x2) +(12x0.5) = 60 +6 = 66 Deg
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+1 for 66 degree....
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Answer is B - 66 degrees.
12 hours equal 360 degrees -> 2 hours would be 60 degrees. Now we can eliminate answer choice A, which equals 60.
1 hour= 60 minutes = 30 degrees, so 12 minutes would be less than 12 degrees, so answer choice C (which equals 72) and D, E (which are larger) are also eliminated. No further calculations are required and B is correct.
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abhishekshannu wrote: Hi there, I can't figure out what's wrong..but..
I understand 360 degrees/ 12 hour = 30 degrees per hour..
but 360 degree/60min = 6 degree per min...
why 1/2?? Hi there, As you wrote correctly, its 30 degrees per hour=30/60 =1/2 degrees per minute (since there are 60 minutes in an hour..) In other words, the correct form is "360 degrees/(12*60)" and not "360 degree/60min".
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hey, the question asks for the the number of degrees in revolving from 12:24 to 2:36 .
lets first calculate how many degrees a hour hand cover in rotating one minute.
hour hand moves (12*60 = 720 minutes) a day. and for covering these 720 minutes, it moves 360 degrees.
so for every minutes it moves 360/720 = 1/2 degrees/ minutes.
here the hour hand moved = 36+ 60 + 30 = 132 minutes
so the hour hand will move 132/2 = 66 degrees.
so correct answer is B.
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