Machine-translated by Google. Questions are authored in English.
Top

Discussion

What is the unit digit of \(9^{99}\)?

  • A.1
  • B.3
  • C.7
  • D.9

Answer: D

The unit digits of powers of 9 alternate:

\[ 9,\ 1,\ 9,\ 1,\ \ldots \]

Odd exponents end in 9. Since 99 is odd, the unit digit is 9.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.