Tides typically range from three to six feet, but while some places sh

Hello Everyone!

Let's take a look at this question, one problem at a time, and come to the correct answer quickly. To get started, here is the original question, with major differences between each option highlighted in orange:

Tides typically range from three to six feet, but while some places show no tides at all, some others, such as the Bay of Fundy, have tides of at least thirty feet and more.

A. some others, such as the Bay of Fundy, have tides of at least thirty feet and more
B. the others, such as the Bay of Fundy, that have tides of more than thirty feet
C. others, such as the Bay of Fundy, have tides of more than thirty feet
D. those at the Bay of Fundy, which has tides of more than thirty feet
E. the ones at the Bay of Fundy have tides of at least thirty feet and more

After a quick glance over each option, it's clear that we have to ways to tackle this question. Whichever method you choose, you'll knock out 2-3 options at once:

1. others / those / the ones
2. at least thirty feet and more vs. more than thirty feet

The easiest place to begin seems to be #2 on our list: at least thirty feet and more vs. more than thirty feet.

The GMAT prefers options that are concise and free of redundancies whenever possible. If we look closely, we can already see a problem with the phrase "at least thirty feet and more" - it's redundant! We could say "at least thirty feet" or "more than thirty feet," which both mean pretty close to the same thing, but to put them together is unnecessary! So let's eliminate options A & D because they are redundant.

(*Note: I do understand that the phrases "at least thirty feet" and "more than thirty feet" mean something slightly different mathematically. "At least thirty feet" means thirty feet and higher, while "more than thirty feet" means anything higher than, but not including, thirty feet. However, since the point of this phrase is to show that some tides are small, yet others are large, this difference isn't really the focus here. What the GMAT is looking for here is concise wording.)

Now that we've eliminated 2 options, let's tackle #1 on our list: referring to others / those / the ones. There are two ways of looking at this:

Option #1: Idiomatic Structure

The idiomatic structure this sentence uses is "some do X, while others do Y." It is not idiomatically correct to say "some do X, while the others do Y" or "some do X, while those do Y." Therefore, you can eliminate options B & D because they're not idiomatic.

Option #2: Correct Usage of the conjunction "but."

We use the coordinating conjunction "but" to combine two independent clauses. What comes before the "but" is already an independent clause (we know this because it's not underlined), so let's make sure the clause after "but" is independent for each option:

B. Tides typically range from three to six feet, but while some places show no tides at all, the others, such as the Bay of Fundy, that have tides of more than thirty feet. --> This is INCORRECT because the clause after the conjunction cannot stand alone!

C. Tides typically range from three to six feet, but while some places show no tides at all, others, such as the Bay of Fundy, have tides of more than thirty feet. --> This is CORRECT because the clause after the conjunction can stand alone!

D. Tides typically range from three to six feet, but while some places show no tides at all, those at the Bay of Fundy, which has tides of more than thirty feet. --> This is INCORRECT because the clause after the conjunction cannot stand alone!

Therefore, you can eliminate options B & D because they also don't follow the rule of using an independent clause after a coordinating conjunction!

There you have it - option C is the correct answer!


Don't study for the GMAT. Train for it.