SOLUTION: The serial number on a $10 bill contains eight non-zero digits. If your $10 bill contains the digit 7 at least once, you win a prize. The probability that your $10 bill will be a p

Algebra ->  Probability-and-statistics -> SOLUTION: The serial number on a $10 bill contains eight non-zero digits. If your $10 bill contains the digit 7 at least once, you win a prize. The probability that your $10 bill will be a p      Log On


   



Question 369915: The serial number on a $10 bill contains eight non-zero digits. If your $10 bill contains the digit 7 at least once, you win a prize. The probability that your $10 bill will be a prize-winning bill is:
Thank you very much!

Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
Consider the complementary event of a 7 NOT appearing as a digit in the 8 digits. We then have 8 choices for filling 8 spaces. The probability that a 7 will not appear is then8%5E8%2F9%5E8+=+%288%2F9%29%5E8, and the probability of a 7 appearing at least once is 1-%288%2F9%29%5E8+=+0.610255656. That is also the probability for a prize-winning bill.