Multiple choice

Directions: Find the missing number in the given series. 64, 65, 61, 70, 54, ___

  1. 78

  2. 74

  3. 79

  4. 75

  5. 77
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C Correct answer
Explanation

The series is 64, 65, 61, 70, 54, ... The differences are +1, -4, +9, -16. The next difference should be +25. 54 + 25 = 79.

AI explanation

The series follows an alternating pattern of adding and subtracting consecutive perfect squares, demonstrated as 64 + 1 = 65, 65 - 4 = 61, 61 + 9 = 70, and 70 - 16 = 54. To find the missing number, you must add the next perfect square, which is 25, to the last term. Therefore, the calculation is 54 + 25 = 79.

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