From the list 13, 15, 17, 21, select all composite numbers.
Note
15 = 3·5 and 21 = 3·7 are composite because they have divisors other than 1 and themselves; 13 and 17 are prime.
From the list 13, 15, 17, 21, select all composite numbers.
15 = 3·5 and 21 = 3·7 are composite because they have divisors other than 1 and themselves; 13 and 17 are prime.