<span>Part A: M = 12x. (x hours at the rate of $12/per hour)
Part B: T = 12 * 30 + 15y. ( 30 hours per week at the rate of $12 per
hour plus y hours at the rate of $15 per hour)
Part C: Let us first find out the amount earned through regular working hours and overtime hours.
Regular hours in a week is 30 at the rate of $12 per hour. It comes to 12*30 = $360
The remaining amount, 510-360 = 150, is earned through overtime. Overtime rate is $15 per hour. So the number of hours worked overtime = 150/15 = 10
Total hours worked during the week = 30 + 10 = 40.</span>