Answer :
Given:
The expression of fuel is given as,
[tex]f(x)=\frac{1}{150}x^2+\frac{1}{3}x\text{ . . . . . (1)}[/tex]The objective is to find the efficiency when x = 30mph.
Explanation:
To obtain the efficiency, substitute x=30 in equation (1).
[tex]f(30)=\frac{1}{150}(30)^2+\frac{1}{3}\times30[/tex]On further solving the above equation,
[tex]\begin{gathered} f(30)=\frac{900}{150}+10 \\ =6+10 \\ =16 \end{gathered}[/tex]Hence, the fu