Use reasoning to lead to the answer of the following question:
Mark constructed a deck that was 30 feet by 40 feet. It cost $3 per square foot. He then paid an extra $1 per square foot for sealant. How much did he pay?

4800
The deck is 30 * 40 = 1200 square feet.

He pays 3 + 1 = $4 per square foot.

So he paid 1200 * 4 = $4800.

.

So, the answer is 4800