Question

check whether 3x5x7x11x13 a composite no. or a prime no. give reason

Answer 1

A prime number has only two factors, i.e. 1 and the number itself. The result obtained is 15015. 15015 comes in other tables such as 5 and 15. Hence it is a composite number.

Answer 2

this is by arithmetic formula
every composite numbers can be written in product of primes
here all are rimes given
that means wen we multiply we get composite number
therefore 3*5*7*11*13 is a composite number

no need to multiply and struggle hard just remember statement buddy