Answer:
Should be 4.0(Not sure tho. my thought process is complicated but to me it makes sense)
Explanation:
If y=10 and x =2.5, if y were to = 20, then x would equal 5. so you take that ratio, and say 6 is 3/5's the way to 10, so you also divide 2.5 by 3/5
you get 1.5, you add that to x already and you get 4.0
so if y=16, x should =4.0