Question

A scuba diver descends 10 ft in an hour.

If he is at -40 feet, how many hours has he been descending?

Answer 1

the answer is 4 hours lol

Answer 2

He has been descending for 4 hours.

Explanation:

10 ft / 1 hr → 40 ft / 4 hr

You can think of this in terms of ratios. Another way to think about this is: After one hour passes, you descend 10 ft. Another hour passes, you descend 20 ft. So on so forth.