SOLUTION: 3,7,17,39,85,?

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Question 842485: 3,7,17,39,85,?
Answer by TheInstructor(29) About Me  (Show Source):
You can put this solution on YOUR website!
Hi,
Firstly this is not sequences and series, simply asking you to find the next number.
Attempt to find the difference betweeen the numbers
7 -3 = 4
17-7 = 10
39-17 = 22
85-39 = 46
Calculate the differences between: 10-4 = 6 , 22-10 = 12 , 46- 22 = 24 (Notice the pattern!!!!)
Therefore since the difference is being multiplied by 2, your next number's difference will be 48
So 85+ 48 = 133