5z^2 + 16
a coefficient is a number multiplied by a variable (a letter). so there is only ONE coefficient in this expression and it is 5.
I think you forgot to post the figure because i do not see any sort of figure.
Answer:
0.80 for 0.5 mile
0.80/0.5 for 1 mile
18.5 × 0.80/0.5 for 18.5 mile
Use calculator and you answer will be 29.6
Here it is!