A clock is set so that every 4th tick is silent. If the clock ticks 10 times per minute for 7 minutes, how many silent ticks were made?

Step-by-step solution

1. Calculate total ticks in 7 minutes: $10\times 7=70$ ticks.
2. Determine how many times the 4th tick occurs: count multiples of 4 up to 70, which is $\lfloor 70/4\rfloor =17$.
3. Thus, 17 silent ticks occurred.

Concept tested: Counting silent ticks over a period

Published 16 October 2026 · How this solution was prepared and checked