Depends on many factors. Cars MPG, cost of gas, how you drive, weather, etc
That depends on your fuel mileage.
Trivially little if you got on your bike!
$300.15
$78.34
Depends how the driver drove the car.
From Cardiff to Glasgow is some 400 miles and would cost about £75 in petrol.
It would cost (2.4) times (the cost of one gallon petrol). Also, add cost of tolls, food, etc.
Not very much. Between $13.00-14.00.
5.54
84.4875
It depends on the cost of said petrol and the efficiency of the vehicle in "miles per unit of petrol". You didn't supply enough information.
That depends how many miles per gallon you travel.