Answer:
. Which means that Frank has been travelling out of the town 3 days for each five days.
Explanation:
The fraction (
) is obtained by dividing the number of days that Frank has been out of town (18 days) in the given period (30 days). That is to say:

- Out-of-the-town period, measured in days.
- Given period, measured in days.
If
and
, then:


Which means that Frank has been travelling out of the town 3 days for each five days.