While in europe, if you drive 115 km per day, how much money would you spend on gas in one week if gas costs 1.10 euros per liter and your car's gas mileage is 38.0 mi/gal ? assume that 1euro=1.26dollars?

First off, we should convert those kilometers to miles, for the sake of easier calculation.

We’ll take that 1km is 0.621 miles. So, daily, you would be travelling 0.621*115, or 71.415mi. Over the course of one week, that would be 71.415 * 7, or 499.905mi.

Next, we should convert 1.10e to dollars.
If 1 euro is 1.26 dollars, then we can say that 1.10e is x dollars.

euros dollars
1 1.26
1.10 x

x=1.26*1.10 (we divided x with the number diagonal to it, and multiplied the other two numbers diagonally, like criss-cross)

x=1.386 dollars

So, its 1.386 dollars per liter. We’ll take that 1 liter = 0.264 gallons.

Our car can run 38 miles on 1 gallon of gas, so we need to find out how many gallons we need for 499.905mi.

38mi 1 gallon
499.905mi x gallons

x=499.905/38=rougly 13.16 gallons

13.16gal is about 49.816 liters, so we would be spending roughly 54.8 euros, or around 76 dollars (if we multiply 54.8e by 1.386 dollars). Please check this, I’m not 100% sure everything is correct

Common ratio, exponential function, half-life that's all i have so