Find the average of all prime numbers between 20 and 40.

Correct option is C

Given:

Prime numbers between 20 and 40

Formula Used:

Average = $$\frac{\text{Sum of primes}}{\text{Number of primes}}$$​​

Solution:

Prime numbers between 20 and 40 are:

23, 29, 31, 37

Sum = 23 + 29 + 31 + 37 = 120

Number of primes = 4

Average = $$\frac{120}{4}$$​ = 30