Question

The minute hand of a clock moves from 3 o'clock to 6 o'clock, or 1/4 of a complete revolution. Through how many degrees does it move?

Answer 1

A full revolution is equal to 360 degrees. Thus, rotating a quarter of a full revolution would put it at 360/4 = 90 degrees.

Answer 2

Well, there's 360 degrees in a full circle. 
If the hand moves 1/4 of a complete revolution, divide 360 by 4.

$360\div4=90$

The minute hand moved 90 degrees.