Question

7 x 11 x 13 x 15 + 15 is : (a) composite number (b) prime number (c) neither composite nor prime (d) none of these

Answer 1

Answer:

Composite number

Step-by-step explanation:

7×11×13×15 + 15

= 15(7×11×13 + 1)

Since the given number has factors apart from 1 and itself, it is a composite number.

Answer 2

Answer:

7 x 11 x 13 x 15 + 15 is a composite number.

Step-by-step explanation:

• In the given expression, we can see there are two terms and 15 appears in both the terms.

       So, 7 x 11 x 13 x 15 + 15 = 15 x (7 x 11 x 13 + 1)

• Now, 15 x (7 x 11 x 13 + 1) can be seen as a product 3 x 5 x (7 x 11 x 13 + 1). It means it's a product of two or more prime numbers.
• Also, we know that the product of two or more prime numbers is a composite number.

Hence, 7 x 11 x 13 x 15 + 15 is a composite number.