This question is obviosly missing an ending but, I bet you will have to divide.
Answer:
23
Step-by-step explanation:
1) (10*0.5)+(-6*-3)
2) (5)+(18) (The 18 isn't negative because of the rule that states "A negative and a negative will become positive"
3) 5+18=23
Answer:
79.5%
Step-by-step explanation:

I think it is going to be 3.55 for each notebook and 1.9 for each pen
Well, considering this is a Math Joke, I believe, the answer is, "Because it is the scenter." Or (Center).
Hoped this helped! :)