11. An ancient problem. How many kilometers will a traveler cover in 17 days, spending 10 hours a day on this, if he has already traveled 112 kilometers in 29 days, spending 7 hours each day on the road?
11. Since the traveler has traveled 112 km in 29.7 hours, in $17 \cdot 10$ hours he will travel $\frac{112 \cdot 17 \cdot 10}{29 \cdot 7}=93 \frac{23}{29}$ km (from a French textbook of the $X I X$ century - speeds were not very high back then).