Answer:
17 and 18
Step-by-step explanation:
Writing every 2 digit number gives us :
10-99 including 10 and 99
For the first one we are looking for numbers where the number 3 appears only once so 33 would be invalid.
13,23,30,31,32,34,35,36,37,38,39,43,53,63,73,83,93
There are 17 2-digit numbers that have 3 exactly once
For the second one we are looking for number where the number 3 appears a minimum of once so 33 would be valid :
13,23,30,31,32,33,34,35,36,37,38,39,43,53,63,73,83,93
There are 18 2-digit numbers that have 3 at least once
Hope this helped and have a good day
