question: Billy is buying some candy with $10 his father gave him. The candy costs $1.5 a pound. After buying candy, he takes half his change and spends it on gumballs, which cost $.05 each. If he bought 40 gumballs, how many pounds of candy did he buy?
answer: He spent $2 on gumballs because 40 x .05 = <<40*.05=2>>2
  He had $4 in change because 2 / .5 = <<2/.5=4>>4
  He spent $6 on candy because 10 - 4 = <<10-4=6>>6
  He bought 4 pounds of candy because 6 / 1.5 = <<6/1.5=4>>4
  #### 4