Why are 35 57 87 composite numbers?
All numbers having more than two factors are composite
numbers.
Factors of 35 are 1, 5, 7, and 35.
Factors of 57 are 1, 3, 19, and 57.
Factors of 87 are 1, 3, 29, and 87.
Since 35, 57, and 87 all have more than 2 factors, they are
composite numbers.