Answer:
8
Explanation:
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 easily get rid of all the even numbers except 2 and then look at the numbers to see if they can be divisible by anything but 1 and its self. then you will get the answers 2, 3, 5, 7, 11, 13, 17, and 19