3. A sports memorabilia retailer purchased a shipment of vintage NHL hockey sweaters for a total cost of $2730.Fifteen of these sweaters were in terrible condition, and could not be resold. The rest were sold for a total of $3900,making a profit of $36 per sweater. Using this information,determine how many sweaters were in the original shipment, and what was the unit cost of each sweater.

Fig: 1