Question

Is 7× 6 × 5 × 4 × 3 × 2 × 1+ 5 a composite number? Justify your answer.
(class 10 CBSE SAMPLE PAPER 2017-18 MATHS)

Answer 1

SOLUTION:


7× 6 × 5 × 4 × 3 × 2 × 1+ 5


= 5040 +5=5045


= 5045 = 5×1009


We know that a number is called a composite number if it has at least one factor other than 1 and the number itself.


Here, 5045 is the product of  2 prime factors 5 and 1009 .


Hence,7× 6 × 5 × 4 × 3 × 2 × 1+ 5 is  a composite number.



HOPE THIS WILL HELP YOU….

Answer 2

7× 6 × 5 × 4 × 3 × 2 × 1+ 5

= 5 ( 7× 6 × 4 × 3 × 2 × 1 + 1 )

= 1 × 5 × ( 7 × 6 × 4 × 3 × 2 × 1 + 1 )

As the expansion 7× 6 × 5 × 4 × 3 × 2 × 1+ 5 has more than two factors .Its a composite number. A prime numbers has only two factors, one and itself .A composite number has more than two factors