Question

Why 7*6*5*4*3*2*1+5 is composite number?

Answer 1

Answer:

Given:

• number 7*6*5*4*3*2*1+5

To prove:

•   that the given number is composite.

Pre-requisite Knowledge:

Composite number: The number having more than two factors .That is the number should have at least three factors.

For instance, 4 , 6 ,8,9,10 ......

Solving Question:

 We are given the number and to improve that it is composite number, we have show that this number has at least three factors.

Solution:

7*6*5*4*3*2*1+5

Take out 5

⇒ 5(7*6*4*3*2*1 + 1)

or, 5( 1008 + 1)

or, 5 (1009) *1

Hence, this number is a composite as it has more than two factors.