GMAT Sentence Correction (SC) | Re: slim/fat/ chance

DearKaal ,

I'm happy to help.

First of all,"slim chance " and"fat chance " are highly colloquial phrases that appear in American conversation English, but these arevery informal and wouldnever appear on the GMAT. BTW, in American spoken English, "fat chance" is almost always used sarcastically to implie its opposite.
"Is Chris going to watch the baseball game with us? quot; -- " Fat
...

---