A number is selected at random from the numbers 1 to 20. What is the probability that it is a prime number?

We are given numbers from 1 to 20.

We have to find the probability that the number drawn from these numbers is a prime number. The prime numbers between 1 and 20 are 2, 3, 5, 7, 11, 13, 17, 19.

So, there are 8 prime numbers between 1 and 20. Now, the probability is given by,

Probability,  P = $\frac{Number of outcomes}{Total outcomes}$

Here, the number of outcomes = Number of prime numbers between 1 and 20

⇒ 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑜𝑢𝑡𝑐𝑜𝑚𝑒𝑠 = 8

And total outcomes = 20 (as there are 20 numbers under consideration) 

So,  P  = $\frac{8}{20}$

P = $\frac{2}{5}$

So, the probability that the drawn number is a prime number is $\frac{2}{5}$

Hence, the correct option is (c) $\frac{2}{5}$.