Seven and a Half Degrees at a Quarter Past Three
At 3:15 the minute hand is on the 3 and the angle between the hands looks like zero. It is 7.5 degrees, or pi/24 radians, because the hour hand crawls a quarter of the way from the 3 to the 4 while the minute hand travels a full lap. The zero answer is exact for a clock whose hour hand waits on each numeral and jumps, which is not a clock that exists.