Question

explain why 3*5*7+7*11 is a composite number

Answer 1

3*5*7+7*11
7(3*5*1+1*11)
7(165+1)
7(166)
Now factorise 166.......

So, 7(2*83)
Which is a prime no.

So, 3*5*7+7*11 is a composite no.