Question

You load boxes onto an empty truck at a constant rate. After 3 hours, there are 100 boxes on the truck. How much longer do you work it you load a total of 120 boxes? You work hour(s) longer Justify your answer

Answer 1

36 minutes

Explanation:

100 boxes in 3 hours is a rate. It is how fast you are working in boxes per hour 100/3 boxesperhour.

But 3 doesn't go into 100 very neatly and its going to make all kinds of ugly fractions or decimals. But lets look at minutes. 3 hours is 3 × 60 minutes (bc there's 60 minutes in an hour) So you loaded 100 boxes in 180 minutes. That's 100/180 boxes per minute.

100/180 = 10/18

10/18 means 10 boxes in 18 minutes.

So times 2 on the top and the bottom gives you 20/36.

20/36 means 20 boxes in 36 minutes.

This is your answer. It will take 36 minutes to load 20 more boxes.