There are 75 numbers between 1 and 100 that are not prime.
According to the reference provided, there are 25 prime numbers between 1 and 100. Therefore, the number of non-prime numbers within that range can be calculated as follows:
Total numbers - Prime numbers = Non-prime numbers
100 - 25 = 75
This confirms that 75 numbers between 1 and 100 are not prime. The reference also notes that the probability of a number between 1 and 100 not being prime is 75/100, or 3/4.
