by Sage Pearce-Higgins Tue May 22, 2018 7:31 am
It's great to learn from the correct answers of GMAT problems, especially official ones. If a construction is used here, then you're very likely to see it in a real GMAT test. Here, "far less than four quarters" is clearly giving some information about the weight of the dollar coin. It would be okay to see it as modifying "8.7 gms", but probably most logical to see it as modifying "weighs 8.7gms". After all, the comparison is between what the dollar coin weighs, and what four quarters weigh. The absolute grammatical truth shouldn't worry us too much; after all, we're trying to solve GMAT problems, not become academic grammarians. I agree that part of my instinct expects to see "far less than four quarters do", i.e. emphasizing that we're comparing what the two things weigh. However, the meaning of the sentence isn't ambiguous and clearly GMAT deems this construction to be acceptable.