Three of them.
3 composite numbers, 21, 22, and 24, are greater than 20 but less than 25.
There are 15 composite numbers greater than 50 but less than 70
24
Five.
There are 18.
There are 7 composite numbers greater than 20 and less than 30:21, 22, 24, 25, 26, 27, 28
2
there are 4. 11,13,17,19
All of them except for 23 which is a prime number
1260 of them.
74
There are 15 prime numbers and 34 composite numbers because 1 is not considered to be a prime or composite number