Multiple choice

Find the missing number in the following series. $5, 7, 10, 15, 22, ?, 46$

  1. $31$
  2. $35$
  3. $33$
  4. $37$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The differences between consecutive terms are: 7-5=2, 10-7=3, 15-10=5, 22-15=7. The pattern in differences: +1, +2, +2. Continuing this: 7+2=9, so next difference is 9. 22+9=31. Then 31+11=42, and 42+13=55. But answer should be 33. Let's check: 5,7,10,15,22 - differences are 2,3,5,7 (primes!). Next prime after 7 is 11. 22+11=33. Then 33+13=46. This fits! The differences are consecutive prime numbers: 2,3,5,7,11,13.

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