Question

Check whether 5×3×11+11 and 5×7+7×3+3 are composite number and justify.

Answer 1

A composite number is one which has factors other than 1 and the number itself.

Lets check whether the numbers 5 × 3 × 11 + 11 and 5 × 7 + 7 × 3+3 are composite are not

5 × 3 × 11 + 11 = 15 × 11 + 11 = 165 + 11 = 176

and its factors are 1× 2 × 2 × 2 × 2 × 11. Thus, it is composite number as it has factors other than 1 and itself.

Another number is 5 × 7 + 7 × 3 + 3 = 35 + 21 + 3 = 35 + 24 = 59

Its factors are 1 and the number 59 itself so it is not a composite number.