Multiple choice

Find the next term in the following number series: 5, 15, 9, 27, 21, 63, 57, ___

  1. 171

  2. 161

  3. 153

  4. 120

  5. 104
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A Correct answer
Explanation

The pattern is: *3, -6, *3, -6... 5*3=15, 15-6=9, 9*3=27, 27-6=21, 21*3=63, 63-6=57, 57*3=171.

AI explanation

The series is created by alternating between multiplying by 3 and subtracting 6. The first term 5 multiplied by 3 gives 15, then 15 minus 6 gives 9, then 9 multiplied by 3 gives 27, and so on. Following this alternating pattern, the last term 57 must be multiplied by 3, yielding 171.

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