Does this represent a function?

The diameter of a table is 5 feet. what is the circumference

Solve - pv + 40 < 65 for v solve 7w - 3r = 15 for r

This week, conrad will work 1 3/4 times longer than last week. giovanni will work 1 1/3 times longer than last week. sally will work 2/3 the number of hours she worked last week. match each employee's name to the number of hours he or she will work this week