Maths question please!!

Work out how much fuel fills the tank - and how many miles that lasts

work it out for the way there plus parking and divide by amount of people traveling

and for way back just fuel?

Dunno if that helps ???

Ok, working on my car which costs approx 15p/mile (golf with a 1.6 petrol engine, based on average mpg and current petrol prices) each car will use just over £80 of petrol plus £20 in parking. Split equally between 7 people (2 cars x £100/7) you should all pay approx £28.50. That's not allowing for depreciation, wear and tear, etc on the vehicles.

Less scientifically though I think it depends on who people are, their financial situation and how it works within the group as to who should contribute how much. Have you offered to drive or has someone told you you're doing it? Have you asked if people will be happy to contirbute towards petrol, daft as it may sound, I have friends who would happily jump in with me assuming it was a freebie on the basis that I'd be driving anyway but would make alaternative plans if I suggested them contributing. I don't think it would be unreasonable to ask people to put in but maybe let them decide how much (if you can afford that).