Question

explain why 11 X 13X15X17+17 is composite number
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Answer 1

Step-by-step explanation:

11∗13∗15∗17+17=17(11∗13∗15∗1+1)

Now, 11∗13∗15∗1 is a product of odd numbers which is always odd.

Thus, we have 17∗(odd+1)

=odd∗(odd+odd)

=odd∗even

=even

Now, 2 is the only prime number that is even. Hence, given number cannot be prime and is therefore composite.