The total: $36+16+1=53$ , Jack\textquotesingle s location: $$(53-1)\div2=21$$, so there are $15$ people between Jack and Rose. 
Jason and Ross are in line to check tickets. There are $36$ people in front of Jason and $16$ people behind. Ross happens to be in the middle of the entire line. How many people are there between Ross and Jason?~(adapted from 2000 Math Kangaroo Problem, Level 3 - 4, Question \#12) 
a. $$18$$ 
b. $$17$$ 
c. $$16$$ 
d. $$15$$ 
e. $$14$$ 