2. To walk 4 km, ride 6 km on a bicycle, and drive 40 km by car, Uncle Vanya needs 2 hours and 12 minutes. If he needs to walk 5 km, ride 8 km on a bicycle, and drive 30 km by car, it will take him 2 hours and 24 minutes. How much time will Uncle Vanya need to walk 8 km, ride 10 km on a bicycle, and drive 160 km by car?
# Answer: 5 hours 48 minutes. (5.8 hours)

## Solution:

Let $\frac{1}{x}, \frac{1}{y}, \frac{1}{z}$ be the walking speed, cycling speed, and driving speed, respectively. Then, according to the problem, we can set up the following system:

$$
\left\{\begin{array} { l } 
{ 4 x + 6 y + 4 0 z = 1 3 2 , } \\
{ 5 x + 8 y + 3 0 z = 1 4 4 . }
\end{array} \Rightarrow \left\{\begin{array} { c } 
{ 2 x + 3 y = 6 6 - 2 0 z , } \\
{ 5 x + 8 y = 1 4 4 - 3 0 z . }
\end{array} \Rightarrow \left\{\begin{array}{l}
x=96-70 z \\
y=40 z-42
\end{array}\right.\right.\right.
$$

Therefore, $8 x+10 y+160 z=8(96-70 z)+10(40 z-42)+160 z=348$ minutes. 348 minutes $=$ 5 hours 48 minutes.