Multiple choice general knowledge math & puzzles

  1. The numbers 4 and 6 are the first two numbers that are the averages (or the means) of two consecutive prime numbers that differ by 2. I am the third number that has the same properties. What number am I?

  1. 9

  2. 7

  3. 12

  4. 15
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The first two numbers are 4 (average of 3 and 5) and 6 (average of 5 and 7). The next pair of twin primes is 11 and 13, whose average is 12. Option 9 is not the average of any twin prime pair.

AI explanation

The average of twin primes (primes differing by 2) gives the sequence in question: (3,5) average to 4, and (5,7) average to 6 — the first two examples given. The next pair of twin primes after (5,7) is (11,13), whose average is (11+13)/2 = 12, making 12 the third number with this property.

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