financial analysis question:

2) Handy Doll Manufacturing has the following information: The average doll sales price is $50. Raw materials for a doll is $10. It takes 30 minutes to assemble a doll. Production labor is $15 per hour. Operating costs are as follows: Salaries $8,000 per month, Insurance $1,200 per quarter, rent $1,000 per month, utilities $700 per month. How many dolls must be sold per month to break even? How many dollars in sales does this represent? What is the contribution margin for EACH doll