Biff rented a pretzel stand and sold pretzels at the beach yesterday. He sold 200 pretzels for $4 each.

Here is a list of all of Biff's costs:

Pretzel stand rental fee: $80

Wholesale food costs: $240

Paper containers, napkins and other supplies: $53

Biff could have worked for his buddy Jesse as a landscaper yesterday and earned: $100

Now please answer these 3 questions:

1. How much was Biff's implicit cost? 

2. Calculate Biff's total profit. 

Hint #1: Total profit = total revenue - total cost

Hint #2: Include ALL of Biff's costs in your calculation, including implicit cost

3. Calculate Biff's profit margin.