8. Ryan's car averages 40 miles per gallon of gasoline, Tom's car averages 10 miles per gallon, Ryan and Tom drive their respective cars the same distance. Considering both cars together, on average, they can travel ( ) miles per gallon of gasoline.
(A) 10
(B) 16
(C) 25
(D) 30
(E) 40
8. B.
$$
\frac{2}{\frac{1}{40}+\frac{1}{10}}=16
$$