Two cars travel from different locations at constant speeds. To meet each other after starting at the same time, they take $1.5$ hours if they travel towards each other, but $10.5$ hours if they travel in the same direction. If the speed of the slower car is $60 \mathrm{~km} / \mathrm{hr}$, then the distance traveled, in $\mathrm{km}$, by the slower car when it meets the other car while traveling towards each other, is
- $100$
- $90$
- $150$
- $120$