Is there more composite numbers then prime and why?

Answer 1

Sieves of Eratosthenes is a good way to understand why:

For example:

Write down all numbers from 1 to 100

2 is prime, so all its multiple are composite, all even numbers except 2 are composite, so erase them. Half of the numbers are already erased

3 is prime, so all its multiple are composite, so erase them. A bit less than one third of the remaining number are erased (multiples of 6 have already been erased)

5 is prime, so all its multiple are composite, so erase them....

and so on with 7 and 11....

Each time a Prime number is found all its multiples are to be erased from the list.

Thus there are more composite numbers (erased ones) than primes.