Sections A – Data Interpretation and Quantitative Ability

31. In a clock having a circular scale of twelve hours, when time changes from 7:45 A.M. to 7:47 A.M., by how many degress the angle formed by the hour hand and minute hand changes?

A. 10 B. 11 C. 12 D. 15 E. None of these

Solution:

The hour hand covers 360° @ 12 divisions in 12 hours

The hour hand covers in 60 minutes.

The hour hand covers per minute

The minute hand completes one revolution or 360° in 60 minutes

\ the minute hand covers 6° per minute

Therefore every minute the angle between the two hands changes by 6° – = = .

\ from 7 : 45 AM to 7 : 47 AM i.e., in 2 minutes, the angle between the two hands will change by ´ 2° or 11°. Choice (B)