Question #48081

1 Answer
Sep 26, 2015


The European car is more efficient.


The problem actually tells you what you need to do in order to solve this problem.

I will convert the US units to metric units using the conversion factors

#"1 mi" ~= "1.609 km" " "# and #" " "1 gal" ~= "3.7854 L"#

So, convert the mileage of the American car from miles per gallon to kilometers per liter

#30color(red)(cancel(color(black)("mi")))/color(red)(cancel(color(black)("gal"))) * (1color(red)(cancel(color(black)("ga"))))/"3.7854 L" * "1.609 km"/(1color(red)(cancel(color(black)("mi")))) = "12.75 km/L"#

Rounded to one sig fig, the number of sig figs you gave for the mileage of the American car, you will get

#"30 mi/gal" = "13 km/L"#

This means that the European car is more fuel-efficient, since you can cover more distance using one liter of fuel

#"22 km/L" > "13 km/L"#