How many prime numbers exist between 20 and 60, and what is the average of these prime numbers?

A7, 41.5

B9, 40.33 ✓ Correct

C8, 39.5

D10, 42.33

Correct answer: (B) 9, 40.33

Explanation

There are 9 primes with average 40.33.

primes 20 to 60: 23, 29, 31, 37, 41, 43, 47, 53, 59.

their count = 9.

their sum = 363.

average = 363 / 9 = 40.33.

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