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39 votes
39 votes
Don't get this question

Don't get this question-example-1
User Fouric
by
2.7k points

1 Answer

11 votes
11 votes

Answer:

17 and 18

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

User Jose Paredes
by
2.6k points
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