Multiple choice

Find the missing term in the following series. 11, 12, 28, 93, 388, ?

  1. 2126

  2. 1865

  3. 1965

  4. 2031

  5. 2131
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C Correct answer
Explanation

The pattern is: 11*1+1=12; 12*2+4=28; 28*3+9=93; 93*4+16=388; 388*5+25=1965.

AI explanation

The series follows a pattern where each term is multiplied by an increasing integer and then a decreasing integer is subtracted: 11 times 1 minus (-1) equals 12, 12 times 2 minus (-4) equals 28, 28 times 3 minus (-9) equals 93, and 93 times 4 minus (-16) equals 388. Applying the same logic, the multipliers increase by one (1, 2, 3, 4, 5) while the subtracted squares are (-1, -4, -9, -16, -25). The missing term is 388 times 5 minus (-25), which calculates to 1940 + 25. The result is 1965.

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