Question

Through how many degrees does the hour hand of a clock turn from 4:00 pm to 8:00 pm of the same day?

Answer 1

`120^@`

Explanation:

As shown in Fig 1, a clock is divided into 12 sectors. Each sector represents `30^@ (360^@/12=30^@)`. This means the hour hand turns `30^@` per every hour.

At 4pm, the minute hand points to 12 and the hour hand points to 4, so there are 4 sectors between them, so they are `4xx30=120^@` apart.
At 8 pm, the minute hand points to 12 and the hour hand points to 8,
so there are 8 sectors between them, so they are `8xx30=240^@` apart.
So from 4pm to 8 pm of the same day, the hour hand turns `240-120=120^@` .

Footnote:
The hour hands turns `30^@` in one hour. So in four hours (form 4 pm to 8 pm), it turns `4xx30=120^@`