Why using the contribution margin technique

Question

In the month of June, Barbara's beauty saloon gave 2,700haircuts, shampoos, and permanent at an average price of $30.During the month, fixed costs were $18000 and variable costs were70% ofsales

Instructions:

1. Determine the contribution margin in dollars per unit and as aratio
2. Using the contribution margin technique, compute the break-even point in k dollars and in units