need help on this one please

Portia Company is a retailer of hammers. Portia pays $4.35 for each hammer and sells them for $8.90. Monthly fixed costs are $27,300. The hammer cost is the only variable cost. a. What is the contribution margin per unit? (Round your answer to 2 decimal places.) Contribution Margin per unit b. What is the break-even point in units? (Do not round intermediate calculations.) Break-Even Point units c. How many units will Portia need to sell to earn target profit of $29,575? (Do not round Intermediate calculations.) Total Number of Units