At 8 o'clock, the obtuse angle between the hands of the clock is 120°. In the following six minutes, the minute hand turns through an angle of 36° whilst the hour hand turns through an angle of 3° in the same direction (clockwise!). So the obtuse angle between the hands increases by 33°, to 153°.

This problem is taken from the UKMT Mathematical Challenges.

You can find more short problems, arranged by curriculum topic, in our short problems collection.