50 of them.
50.
Well, for every 10 numbers there are 5 even numbers (2,4,6,8,10). So if you include beginning and ending numbers, the even numbers from from 100 to 150 are:100102104106108110112114116118120122124126128130132134136138140142144146148150
There are 100 even numbers between 1 and 200 (inclusive).
300.
Excluding 22 and 100, there are 39
Every second number is Even. So there are 50 even numbers from 1 to 100 if you include 100. If you do not include 100 in the count there are obviously 49. The wording of the question is not clear on whether 100 is to be included or not.
The only even prime number (not only from 1 to 100, but in general) is 2. All other even numbers are multiples of 2, and therefore, by definition, not prime numbers.
The first 100 even numbers are: 2 468101214161820222426283032343638404244464850525456586062646668707274767880828486889092949698100102104106108110112114116118120122124126128130132134136138140142144146148150152154156158160162164166168170172174176178180182184186188190192194196198200.
The first 100 whole, even numbers are: 2468101214161820222426283032343638404244464850525456586062646668707274767880828486889092949698100102104106108110112114116118120122124126128130132134136138140142144146148150152154156158160162164166168170172174176178180182184186188190192194196198200.
even numbers 1-100
There are exactly 50 even numbers if you include 100. There are exactly 50 odd numbers if you include 1.
46 if you include 10 and 100, 44 if you don't.