SOLUTION: Select the option for “?” that continues the pattern in the question. 3, -6, 12, 4, 20, ?

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Question 1062326: Select the option for “?” that continues the pattern in the question.
3, -6, 12, 4, 20, ?

Answer by Edwin McCravy(20059) About Me  (Show Source):
You can put this solution on YOUR website!
Select the option for “?” that continues the pattern in the question.
3, -6, 12, 4, 20, ?
2nd term minus 1st term = -6-3 = -9
3rd term minus 2nd term = 12-(-6) = 12+6 = 18
4th term minus 3rd term = 4-12 = -8
5th term minus 4th term = 20-4 = 16
6th term minus 5th term = ?-20 = ?


The sequence of differences is -9, 18, -8, 16

That has the pattern:  -9, 18, -8, 16, -7, 14, -6, 12, ...

So there must be a -7 after the last = sign

2nd term minus 1st term = -6-3 = -9
3rd term minus 2nd term = 12-(-6) = 12+6 = 18
4th term minus 3rd term = 4-12 = -8
5th term minus 4th term = 20-4 = 16
6th term minus 5th term = ?-20 = -7 
                          ?-20 = -7
   Add 20 to both sides
                             ? = -7+20
                             ? = 13

Edwin