Select all prime numbers from the list: 2, 9, 13, 15.
Note
2 and 13 are prime because their only positive divisors are 1 and themselves; 9 and 15 have additional divisors (9 = 3×3, 15 = 3×5) so they are composite.
Select all prime numbers from the list: 2, 9, 13, 15.
2 and 13 are prime because their only positive divisors are 1 and themselves; 9 and 15 have additional divisors (9 = 3×3, 15 = 3×5) so they are composite.