Question

find the largest number that you need to test as a divisor to determine whether each of the following is a prime number 1. 101 2.111 3.397 4. 401 5. 487 6.227 plz explain
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Answer 1

Step-by-step explanation:

you have to check the divisibility of primes up to square root of the given number.

square root of 10.04....

you have to check divisible by 2,3,5,7 (<10) or not

1)

101 is not divisible 2,3,5,7

so 101 is a prime

2)

111

1+1+1=3

111 is divisible by 3

so 111 is not a prime

3)

397 is a prime it is not divisible by 2,3,5,7,11,13,17,19(<20)

so 397 is prime

4)

401 is a prime it is not divisible by 2,3,5,7,11,13,17,19(<20)

401 is a prime

5)487

is a prime it is not divisible by 2,3,5,7,11,13,17,19(<20)

487 is a prime

6)227

is a prime it is not divisible by 2,3,5,7,11,13(<15)