Question

25. Which one of the following is a prime number?
(a) 161 (b) 171 (c) 173 (d) 221
is there any method to find directly the prime number​

Answer 1

Answer :

Option C is the Correct Answer.

Explanation:

We have to find the prime Number among the given options; So, We will find Square root of prime Number.

√173 = 13.66 i.e 13

Those Prime numbers which are less then 13 are 2,3,5,7,11.

Here, 161 is divisible by 7, and 221 is divisible by 13.

Therefore, Option C is Correct Answer.

Answer 2

Answer:

161=7×23

171=19×9

221=13×17

Step-by-step explanation:

So 173 is the prime number