1. Tomorrow, the Janssen family is going on a trip by car, and they have a beautiful route in mind for it. The youngest member of the family notes that their planned stop in Germany is exactly halfway along the route. Father responds: "When we cross the border after 150 kilometers tomorrow, our stop will be just one-fifth of the remaining route." How long is the route of the Janssen family in kilometers?
B1. 400 Let the total distance of the route $r$ be the number of kilometers. Then the distance from the Janssen family's house to the stopover is equal to $\frac{1}{2} r$. This is also equal to 150 kilometers plus one fifth of the distance from the border to the final destination, which is $150+\frac{1}{5}(r-150)$. We find that $\frac{1}{2} r=150+\frac{1}{5}(r-150)$. Solving this equation gives $r=400$.