Question

A number is chosen at random from the first 100 positive integers. Find the probability that the number chosen is prime.

1/5

1/4

1/3

Answer 1

Answer: The answer is B). 1/4

Explanation:

Answer 2

The probability that the number chosen is prime is:

`(1)/(4)`

Explanation:

The probability of an event is defined as the ratio of number of favorable outcome to the total number of outcomes.

Here the total number of outcomes are: 100

( Since we have to take first 100 positive integers i.e. 1-100)

Also, the number of favorable outcomes i.e. the number of prime numbers between 1-100 is: 25

( Since, the prime numbers are:

2,3,5,7,11,13,17,19,23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, and 97 )

Hence, the probability that the number chosen is prime is:

`Probability=(25)/(100)\\\\\\Probability=(1)/(4)`