Colin was a professional classical guitar player until his motorcycle accident that left him disabled. After long months of therapy, he hired an experienced luthier (maker of stringed instruments) and started a small shop to make and sell Spanish guitars. The guitars sell for $700 and the fixed monthly operating costs are as follows:

Colin's accountant told him about contribution margin ratios and he understood clearly that for every dollar of sales, $0.60 went to cover his fixed costs, and that anything past that point was pure profit.

How many guitars does Colin have to sell each month to break even?

Rent and utilities $800 Wages and benefits to luthier 2,500 Other expenses 480