Answer is not 0. Remember this is an analog clock.

At 3:15, the minute hand will be precisely at the 15 minute mark while the hour hand will be a little past it. The hour hand will be a quarter of the way between 3 and 4 o'clock. The space between each tick mark on an analog clock is 6 degrees (360 degrees / 60 ticks ex. each minute is 6 degrees apart). There are 30 degrees between 3 and 4 o'clock (6 degrees * 5 ticks). The hour hand will be one-fourth of 30 degrees away from the minute hand - (30 / 4 = 7.5).

Final answer: 7.5 degrees.

Don't feel bad if you didn't get this right away. This was actually a Google technical interview question!