Answer:
Mark will make $80 if he works an eight-hour shift.
Explanation:
For every six hour shift he works, Mark makes $60
This implies that for every hour, he makes $10 ($60/6)
Therefore, for working an eight-hour shift, Mark will make $80 ($10 * 8) or ($60/6 * 8).
We can conclude that Mark's employer pays him $10 per hour.
This hourly rate can be used to work out how much Mark will earn if he works for a month or a year, as the case may be.