I'm having the hardest time with this sequence puzzle. The mobile game I play (which asked me the question) doesn't provide answers or explanations for incorrect answers, and I'm searching online so I can better understand it.
What comes next in this numeric sequence: $ 5, 13, 7.5, 9.5, 10, 6, 12.5, ? $
The multiple-choice answers provided are: $ 2.5,\, 3,\, 3.5,\, 8,\, 13 $
I'm completely at a loss and would appreciate any input. Thank you!