Question

It takes a thermal drill 13 minutes to bore a hole -39 feet from ground level into a glacier. What is the change in depth after one minute?

Answer 1

-3 feet

Explanation:

Divide -39 by 13, since it takes 13 minutes to dig -39 feet:

-39/13

= -3

So, the change in depth after one minute is -3 feet

Answer 2

3 feet

Explanation:

39 divided by 13 = the unit rate per min.

39 divided by 13 = 3