Multiple choice

Directions: Find the missing number in the following series: 1, 5, 14, 30, 55, 91, ?

  1. 130

  2. 140

  3. 150

  4. 160

  5. None of these
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B Correct answer
Explanation

The differences are 4, 9, 16, 25, 36. These are squares of 2, 3, 4, 5, 6. The next difference should be 7^2 = 49. 91 + 49 = 140.

AI explanation

The differences between consecutive terms are 4, 9, 16, 25, and 36, which are the squares of 2, 3, 4, 5, and 6. The next difference must be the square of 7, which is 49. Adding 49 to 91 gives 140.

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