This? year, donnelly,? inc., will produce 60 comma 00060,000 hot water heaters at its plant in? delaware, in order to meet expected global demand. to accomplish? this, each laborer at the plant will work 200200 hours per month. if the labor productivity at the plant is 0.150.15 hot water heaters per labor? hour, how many laborers are employed at the? plant?

Summary of problem.
annual production = 60000 units
work hours per worker = 200*12=2400 hours
productivity = 0.15 unit / person-hour
Need to calculate the number of workers/persons employed.
 
Each unit requires 1 unit / 0.15 unit/person-hour
= 1/0.15 person-hours / unit

60000 unit requires 60000 units * 1/0.15  person-hours/unit
= 400000 person-hours

400000 person-hours requires 400000 person-hours /2400 hours = 166.7 persons 
=>
The plant has 167 labourers  (assuming perfect attendance).