If a and b are two integers such that a is even, b is odd and neither of them leaves a remainder of 1 when divided by 10, what is the units digit of the product ab?
1) The units digit of a^3 is the same as the units digit of a.
2) The units digit of b^4 is the same as the units digit of b.
OAB
1) The units digit of a^3 is the same as the units digit of a.
2) The units digit of b^4 is the same as the units digit of b.
OAB
but finally realized. 
