Using 1,2,4, and 6, the smallest possible 4-digit odd number is...?

Answer 1

2,461 if you must use all the digits.

You need an odd number for the units digit to make it odd, so you must have:
x,xx1

Next you want the thousands digit to be as small as possible. Your remaining digits are 2, 4 and 6, so you want 2.
2,xx1

Similarly you want the smallest possible hundreds digit from the remaining digits.
2,4x1

That leaves one digit to pick for the tens digit:
2,461

Answer 2

1642

Answer 3

2461

Answer 4

2461

Answer 5

2461