Multiple choice general knowledge math & puzzles How many prime numbers are there up to 50? 13 15 17 21 Reveal answer Fill a bubble to check yourself B Correct answer Explanation The prime numbers up to 50 are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, and 47. Counting them results in exactly 15 prime numbers.