Are You The Most (Mental) Mathematical Person In All Of VGChartz? (Read instructions)

[Conegamer]

Well for what it counts I got 24. Do note I'm displeased by the following result:

"15 1/2 + 15 4/5 =
Your answer: 31 3/10
Right answer: 30 3/10"

So, 25 if we count that. Makes me wonder really.