I have what i would call an error in the formula questions, but I think I know what's going on. I created a formula question converting binary to decimal.
Question: Convert [a][b][c][d][e] from binary to decimal.
Even though 'e' (and the other letters) get defined as an integer from 0 to 1 and the question displays correctly, 'e' seems to always be interpreted as the constant e (2.73...) when computing the answer.
I would say either the 'e' we setup needs to 'overwrite' the defined constant OR 'e' should not appear in the defined variables.