Explain simply why 10 is the correct answer to: 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?. Explanation:
There were 15 pounds of rocks in the bucket because 60 / 4 = 15. There were 10 rocks in the bucket because 15 / 1.5 = 10.