Okay I don't know about #2 but:
#1. One of them is not a nickel, so it's a quarter. It says noting about both coins not being nickels.
#3. The surgeon is his mother.
#4. You don't bury survivors. DUH!!
ETA: I must have been writing at the same time as RedVelvet. #2 is a stumper.
Hybrid Mode
