can anyone write a real world situation that can be represented by the given expression

Question

n + 7
5n
1/4n
2n- 12
n/10 + 23

mis-identified on subject line

like write a situation using these numbers

Here is one as an example:
The amount of illuminated tracer ammuntion an aircraft gun uses is once round per ten total rounds per mission, plus twenty-three. What is the algebric expression that expresses the number of tracer rounds used per mission as a function of n rounds shot?