In a city the doors of buildings where numbered from 1 to 100. How many 3’s are there as the door number?  Choose the correct answer:
A) 10
B) 20
C) 30
D) 40
E) 50
We will have the 3’s as follows 3,13,23,30,31,32,33,34,35,36,37,38,39,43,53,63,73,83,93.   In 33 we have 2 3’s. So we get 20 3’s from 1 to 100.   Note: for any numbers from 1 to 9 we’ll get 20 as answer.   Answer 20
<result>B</result>
In a city the doors of buildings where numbered from 1 to 100. How many 3’s are there as the door number?