Question

how many non prime numbers less than 200 whaich are not divisible by 2,3,5,7,9,12

Answer 1

Answer:

1, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 51, 53, 59, 61, 67,69, 71, 73, 79, 83, 87, 89, 91,97,....

...

Step-by-step explanation:

see the last digit and solve it easily.

last digit of a two digit no. is always odd and always prime. Its a Super Easy Method.

Follow

Answer 2

121, 143, 169, 187

4 nonprime numbers only not divisible by 2,3,5,7,9,12 and less than 200

Step-by-step explanation:

Given:

The Nonprime number less than 200

To find:

Nonprime numbers less than 200 which are not divisible by 2,3,5,7,9,12

Solution:

• Nonprime numbers are assigned as composite numbers in 1-100 numbers there are 74 nonprime numbers.
• The smallest factor is 11 as 10 cannot be a factor because it is divisible by 2 and 5.

        ⇒18 < $\frac{200}{11}$

Hence all factors must be laid between 11 and 18.From this 12,14,15,16,18 are neglected because it is divisible by 2,3,5,7,9,12.

Only the possible nonprime numbers are

11×11=121

11×13=143

11×17=187

13×13=169

13×17=221 >200

17×17=289>200

Hence,

nonprime numbers that are less than 200 which are not divisible by 2,3,5,7,9,12 are 121, 143, 169, 187.

4 nonprime numbers.