Question

7*11*13*15+15 is a

a) prime number
b) composite number
c) neither prime nor composite
d) none of these
​

Answer 1

Answer:

a) prime number

Step-by-step explanation:

Hint:

Prime number: A prime number is a natural number greater than 1 that has no positive integer divisors other than 1 and itself. For example, 7 is a prime number because it has no positive divisors other than 1 and 7 itself.

Complete step by step solution:

Given number: 7×11×13×15+15

Simplify the given number

⇒15(7×11×13×1+1)

⇒15(1001+1)

⇒15(1002)

Let the product of the number be (P)

⇒(P)=15(1002)

A prime number is a positive integer that has two factors. One factor will be 1 and another factor will be the number itself. If any number has exactly two factors, then the number will be a prime number else a composite number.

But here we can clearly see that the number has two other factors 15

and 1002

other than 1 and itself (P)

.

Hence, we can conclude that the given number7×11×13+13

is a composite number and not a prime number

Answer 2

Given:

7*11*13*15+15

The correct option is "a"

A number that is divisible only by itself is called prime number.

In the given question 7*11*13*15+15 is a prime number because all numbers has exactly two factors 1 and only it self.

Hence 7*11*13*15+15 is a prime number.