Multiple choice

Find the next term of the series. 2, 5, 13, 31, 69, ___

  1. 111

  2. 121

  3. 128

  4. 147

  5. 154
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D Correct answer
Explanation

The pattern is: 2*2+1=5, 5*2+3=13, 13*2+5=31, 31*2+7=69. The next term is 69*2+9 = 138+9 = 147.

AI explanation

The differences between the terms are 3, 8, 18, and 38. The pattern in these differences is found by doubling the previous difference and adding 2, 4, and 6 respectively. The next difference is 2 multiplied by 38 plus 8, which is 78; adding this to 69 gives 147.

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