How much is fair (either cash or gas money) to pay someone who gave you a ride for 10 miles when you didn't have a car and too much to carry?

I also had my bicycle with me, which fit in the back of their truck. Bags did fit on the handlebars and in the middle (others in my backpack which was completely full), but wouldn't have been able to pedal. Might've been able to walk about 2 - 3 miles to the bus station (and gotten a free ride back to about a mile from my apartment, then walk the rest of the way, but no guarantee I could have gotten back in time to upload, shower, and then go to work. I also can't download anything to my phone - and don't have lyft, uber, etc on it. Gas is a little under 2 dollars a gallon in my area. Please explain your reasoning. Had I walked the whole way back there's no way I would have made it home in time, then lost money from working a shift, even if just a few hours. It's possible but unlikely someone would have seen me walking alongside my bike and offered a ride. I initially offered 10 at what point she was like " That's MORE than enough ".. we agreed on 5 USDollars