Multiple choice

Directions: Find out the missing number in the given series. 1, 5, 9, (?), 25, 37, 49

  1. 17

  2. 16

  3. 15

  4. 14

  5. 13
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A Correct answer
Explanation

The series is 1, 5, 9, ?, 25, 37, 49. Differences: 5-1=4, 9-5=4. If the pattern continues, 9+4=13, 13+4=17. But 17+8=25, 25+12=37, 37+12=49. The pattern is +4, +4, +8, +8, +12, +12. So 9+8=17.

AI explanation

The differences between consecutive terms are 5-1=4, 9-5=4, 37-25=12, and 49-37=12, creating an alternating addition pattern of 4 and 8. Since the last established step was adding 12 (which is 4+8) from 25 to 37, we look at the step from 9 to the missing term, which should be adding 8. Therefore, 9 + 8 = 17, making the result 17.

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