On a recent trip, Cindy drove her car 290 miles, rounded to

This one was very tricky. This is not necc because of the math, but due to understanding what that phrase "must have been between" means. Semantics.

The first thing I did was just read the problem, and without looking at the answers, came up with the following:

285/12.4 and 294/11.5

Then I looked at answers and noticed that there was neither a 294 nor a 12.4 anywhere. That threw me off.

So ... Going back to the question, the phrase is not looking for you to find exactly the range that you worked out. Rather the numbers you came up with must fall within the ranges given in the answer even if the range is much broader than your answer. (D) is the answer.

One way to check is to work things out on a calculator* to get

(a) 290/12.5 and 290/11.5 ~~~> 23.2 and 25.217
...
(d) 285/12.5 and 295/11.5 ~~~> 22.8 and 25.65
(e) 295/12.5 and 285/11.5 ~~~> 23.6 and 24.782

Now, where does 285/12.4 and 294/11.5, i.e. 22.98 and 25.565 fit in? (d)

*Not that you can use a calculator, but this is just to see whats going on.