Worse, if reps can see the answer, then this is equivalent to not hashing the passwords at all since you have a password-equivalent stored in plaintext.
>> they were annoyed about people being able to see part of their SSN
Part of? I worked for AT&T back when they merged with Cingular. We only asked for the last 4 over the phone, but the entire 9-digit SSN was shown in the app. Every single low-level employee had (has?) the entire SSN in front of them. Never dared tell a customer that little fact when they made a fuss over my having access to their last 4.
Worse, if reps can see the answer, then this is equivalent to not hashing the passwords at all since you have a password-equivalent stored in plaintext.