How many prime numbers are there between 20 and 40?
Answer and explanation
Correct answer: C. 4 (23, 29, 31, 37)
- Step 1: Test each number: 23, 29, 31 and 37 have no divisors other than 1 and themselves. Step 2. That makes 4 primes. Answer: 4 (23, 29, 31, 37). Why not the others: 5, 3 and 6 miscount or include numbers like 27 or 39.
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