Please help me solve this statistics problem.

Question

You are an owner of a firm that manages other small manufacturing companies, which pay you to employ temporary salespersons to sell their products. The owner of one of these firms wants to increase their sales and promised to give you a bonus of $40,000 if your temp salespeople sell at least 20 products tomorrow. Assume the cost of a single sales visit a temp sales reps cost you $200 and only a single visit per sales rep per day is allowed. Give that the probability of making a single sale is 0.25, determine the number of temporary salespersons you should plan to hire in order to maximize your profit.