kaplan exam kit

Tree Co is considering employing a sales manager. Market research has shown that a good sales manager can increase profit by 30%, an average one by 20% and a poor one by 10%. Experience has shown that the company has attracted a good sales manager 35% of the time, an average one 45% of the time and a poor one 20% of the time. The company’s normal profits are $180,000 per annum and the sales manager’s salary would be $40,000 per annum. Based on the expected value criterion, which of the following represents the correct advice which Tree Co should be given? A Do not employ a sales manager as profits would be expected to fall by $1,300 B Employ a sales manager as profits will increase by $38,700 C Employ a sales manager as profits are expected to increase by $100 D Do not employ a sales manager as profits are expected to fall by $39,900 i dont know how to solve this question