Based on the context and the answer, generate a question. 

Context: After we finished work on the deck we drove around different places selling watermelons out of the back of Norm 's truck . We got about 150 for $ 100 and sold them 1 for $ 3 or 2 for $ 5 . We figured it 'd be an evening of easy money . Only we only sold about 20 so we did n't even make back our investment .

Answer:

Selling would be easy because the cost of the melons was only about .75 per melon and we could sell them for much more than that .



Why did we figure it 'd be an evening of easy money ?