Question

A number is selected from numbers $1$ to $25$. The probability that it is prime is
A) $\dfrac{2}{3}$
B) $\dfrac{1}{6}$
C) $\dfrac{1}{3}$
D) $\dfrac{5}{6}$

Answer 1

Hint: First of all we will find the prime numbers between the given range and then we will use the formula to get its probability. Probability can be defined as the ratio of the favorable outcomes with the total number of possible outcomes.

Complete step by step solution:
A prime number can be well defined as the positive number which is having exactly two factors. If “n” is the prime number then it has only two factors that is the number itself “n” and the number here, we will find the prime numbers for first twenty-five numbers.
Prime numbers are $2,3,5,7,11,13,17,19,23$
Total number of favorable outcomes are $9$
Total possible outcomes are $25$
Now, the required probability that the number is prime from the numbers $1$ to $25$.
Probability is the ratio of the favorable outcomes with the total number of possible outcomes.
Required probability $ = \dfrac{9}{{25}}$
Hence, from the given multiple choices – no option is the correct.

Note:
Always remember that the range of the probability always lies between the number zero and one. Zero is the probability for the impossible event while one is the probability for the sure event to happen. Also, remember that probability can never be zero. Remember the difference between the prime numbers and the composite numbers.