Question

Which group shows all the whole answer number factors of a composite number?

A. 1,2,3,4,5,8,16
B. 1,2,3,4,5,6,10,20
C. 1,2,3,4,6,8,12,24
D. 1,2,3,4,7,14,28

Answer 1

A complete list of integer factors of a composite, sorted in ascending order will have the property that:
The first number multiplied by the last number equals the composite number,
the second number multiplied by the second last will also equal the composite number,
....
and so on.

If there is an even number of factors, the product of the two middle numbers will also equal the composite number.

If there is an odd number of factors, the composite number is a perfect square, with the middle number being the square-root of the number.

Based on these facts, try to find the answer from the list.