How many of the numbers between 20 and 40 are prime numbers?
A) 3
B) 4
C) 5
D) 6
E) 7
Recall that a prime number is a number that only has itself and 1 as a divisor.
Remove all the evens since the are divisible by 2 (20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40)
Remove all the remaining...