Jim has a pail with rocks in it. The average weight of a rock is 1.5 pounds. A local rock collector agrees to pay him $4 for every pound of rocks. If he makes $60 off the sale, how many rocks were in the bucket?
There were 15 pounds of rocks in the bucket because 60 / 4 = <<60/4=15>>15
There were 10 rocks in the bucket because 15 / 1.5 = <<10=10>>10
#### 10