SOLUTION: How many two-digit counting numbers are not a multiple of 10?

Algebra ->  Probability-and-statistics -> SOLUTION: How many two-digit counting numbers are not a multiple of 10?      Log On


   

Question 667281: How many two-digit counting numbers are not a multiple of 10?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

How many two-digit counting numbers are not a multiple of 10?

Cannot use 0 in the tens place and not using 0 in the ones place...

 9%2A9+=+81

Or

  9%2A10+=+90 two-digit counting numbers minus 9 multiple of tens = 81