The time in the wall-clock is 3.25 the acute angle between the hours-hand and the minutes-hand is

examrobotsa's picture
Q: 105 (IAS/2002)
The time in the wall-clock is
3.25 the acute angle between the hours-hand and the minutes-hand is

question_subject: 

Maths

question_exam: 

IAS

stats: 

0,5,3,3,0,5,0

keywords: 

{'clock': [0, 1, 2, 0], 'acute angle': [0, 0, 1, 0], 'minutes': [0, 0, 1, 1], 'wall': [1, 0, 2, 3], 'hand': [2, 1, 3, 5], 'time': [2, 6, 15, 23], 'hours': [7, 2, 16, 9]}

To understand the answer, let`s take a closer look at each option:

Option 1: 60°. In a clock, a full rotation (360°) is divided into 12 hours, that is 30° for each hour. Here, if the hour hand is at 3 and the minute hand is at 15 minutes (which is a quarter past), then they are one hour space apart which would be a 30° difference, not a 60° difference.

Option 2: 52 ½°. As explained in option 1, one hour space on a clock corresponds to a 30° angle. Thus, a 52 ½° angle would correspond to an interval slightly less than two hours, which is more than the time difference here.

Option 3: 47 ½°. The hour and minute hands at 3:15 are not exactly on the `3` and `15` mark. Remember, the hour hand also moves as minutes pass. When it`s 3:15, the hour-hand is quarter way between 3 and 4. So, the angle is bit less than 30° which is listed as 47 ½°.

Option 4: 42°. This is