Question

Write the natural numbers from 102 to 113. What fraction of them are prime numbers?

Answer 1

1/3

Explanation:

We can list all the numbers from 102 to 113:

To check if each number is prime, we simply have to check divisibility by 2, 3, 5, and 7 — if any of these numbers are not divisible by those, it will have no factors lower than its square root, and will therefore be prime.

102 - composite, multiple of 2

103 - prime

104 - composite, multiple of 2

105 - composite, multiple of 5

106 - composite, multiple of 2

107 - prime

108 - composite, multiple of 2

109 - prime

110 - composite, multiple of 2

111 - composite, multiple of 3

112 - composite, multiple of

113 - prime

4/12 or 1/3 of the numbers in this list are prime.

Answer 2

1/3

Explanation:

So there are 12 natural numbers in total: (113 - 102) + 1

Then there are the prime numbers: 103, 107, 109, and 113

so there are 4/12 prime numbers or 1/3