The sports boosters club is having a bake sale to buy uniforms. They want to raise $250. They need to rent a booth for $20. How many dozen cookies will they need to sell if they charge $3 per dozen?

Which equation could be used to solve this problem?

1. 250 = 3c - 20

2. 250 = 3 - 20c

3. 250 = 20 - 3c

4. 250 = 20c - 3