3. a scuba diver was exploring a reef 32.12 m below sea level. the diver ascended to the surface at a rate of 8.8 m/min. (a) write an equation to model the situation. use the formula d = rt. (b) explain why it is reasonable to write the distance, d, as a positive number. (c) how long did it take the diver to reach the surface?

A. T= d/r
A good way to remember this is by making a pyramid with 3 parts and putting distance at the top and rate and time in the other two parts. This way you can visibly see the equation and use it if you need to find one for rate.

B. It's reasonable to write distance as a positive number because distance is always positive. You are not able to have a negative distance. Imagine someone standing on a side walk. Even if they are not moving, their distance is 0 which is positive. If they move backwards or forwards, their distance is still positive because it is more than that 0 and they are gaining something. 

C. Just plug in the numbers into the formula.
T= d/r
T= 32.12 m /8.8 m/min
T= 3.65 min