Question

Explain why 7x11x13 13 and 7x6x5x4x3x2x1 5 are composite number

Answer 1

Answer:

Step-by-step explanation:

7 and 11 are prime numbers and their product 77 is a composite number

If we consider the number as 7×11×13×13

7×11×13 is again a composite number [∵ product of a prime and composite number is again a composite number.

similarly, 7×11×13×13 is a composite number.

or if we consider the number as 7×11×1313, product of two composite numbers is a composite number .

similarly,

7 is a prime number and 6 is a composite number. their product 42 is composite.

again 7×6×5 -- is a composite number as the product of a composite and a  prime number is composite.

By proceeding like that we can prove that 7×6×5×4×3×2×15 = a composite number.