At 3h00 a clock strikes the bell 3 times. The time between first and last strike is 30 seconds. How long does it take to strike the bell at 12h00?

3 answers

From the timing at 3:00, we see that the intervals are 15 seconds long.

12:00 is 12 strikes, but only 11 intervals.
30 seconds
165 seconds(11*15)