Question

Which of the following numbers is a composite number?

A. 13
B. 19
C. 17
D. 15

Answer 1

whih one can be devided by anothr number that is not its self or 1?

Answer 2

@meilendurcer ?

Answer 3

prime numbers have only 2 factors 1 and the number itself.

e.g. 2 and 3 are prime

composite numbers have more than 2 factors...

e.g. 6 1 x 6 = 6 2 x 3 = 6

you need to find the number with more than 2 factors.

Hint for this question.

add the digits... if you get a multiple of 3.... that is the composite number

Answer 4

Find the number that can be divided by another number into a whole number.
so we'll look at 13 first.

Let n represent a number which we can divide 13 by:
13/ n doesn't equal a whole number. All possibilities lead to decimals.

Repeat for other three choices. Until you find a number in which n is a whole number that results in a quotient that is a whole number.