When a clock strikes, the important thing is not the number of chimes, but the gaps between them. That is the little trap.
The Clock Chimes
Riddle statement
A clock takes 6 seconds to strike 4 o'clock, giving 4 chimes.
How long does it take to strike 12 o'clock, giving 12 chimes?
Show solution
Solution
If the clock gives 4 chimes, there are 3 intervals between them:
between the first and the second; between the second and the third; between the third and the fourth.
Those 3 intervals take a total of 6 seconds.
Therefore, each interval lasts:
$
\frac{6}{3}=2
$
seconds.
When the clock gives 12 chimes, there are 11 intervals between them.
So it takes:
$
11 \times 2 = 22
$
seconds.
Answer: it takes 22 seconds.