You find all the factors of 51. The factors are 1, 51, 3, 17. A Prime number has only 2 factors which are 1 and itself. Composite numbers are everything else except 1, 2, and 0. 51 is COMPOSITE.
51 composite, 61 prime.
51 is composite.
51 is composite, 103 is prime.
prime
prime
It is composite.
composite
It is composite.
51 is a composite number 3 x 17 = 51
51 is a composite number but 61 is a prime number
24 and 51 are composite, 3 is prime.
prime