When 9^100 is divided by 2, what is the remainder?

Answer: A. 1

9 is odd, and any power of an odd number is odd (9¹ = 9, 9² = 81, 9³ = 729, ...). So 9^100 is odd, and an odd number divided by 2 leaves a remainder of 1.

Answering after opening this box earns no Practice Points.