# Math Help - How many primes are there of the form 4x+3 less than 100?

1. ## How many primes are there of the form 4x+3 less than 100?

Hi,

How many primes are there of the form less than ?

Im thinking the answer is 13, but possible it might be 12? depending on whether x=0, prime=3 counts? or maybe neither are right!

help appreciated!

Thanks :-)

2. I asked Mathematica, and it gave the list

3, 7, 11, 19, 23, 31, 43, 47, 59, 67, 71, 79, 83

which contains 13 primes.

3. this should help u

mathforum.org/library/drmath/view/51559.html