8、Person A and Person B ride bicycles from $\mathrm{A}$ to $\mathrm{C}$ at the same time, passing through $\mathrm{B}$ on the way. After riding for a while, A asks B: “How many kilometers have we ridden? ” B replies: “The distance we have ridden is equivalent to $\frac{1}{3}$ of the distance from here to B.” After riding another 10 kilometers, A asks again: “How many kilometers do we still need to ride to reach $\mathbf{C}$? ” B replies: “The distance we still need to ride is equivalent to $\frac{1}{3}$ of the distance from here to B.” The distance between $\mathrm{A}$ and $\mathrm{C}$ is $\qquad$ kilometers (write the answer in fractional form)
The first conversation point is at $\mathrm{D}$, the second conversation point is at $\mathrm{E}$. Let's assume $\mathrm{AD}$ is $\mathrm{x}$, then $\mathrm{BD}$ is $3 \mathrm{x}$; let $\mathrm{EC}$ be $\mathrm{y}$, then $\mathrm{BE}$ is $3 \mathrm{y}$. According to the problem, $3 x+3 y=10$, then the length of $\mathrm{AC}$ is: $4 x+4 y=\frac{4}{3}(3 x+3 y)=\frac{4}{3} \times 10=\frac{40}{3}$.