Chemistry is an experimental science in which a consistent system of measurements is used. Scientists throughout the world use the International System of Units (Systeme international or SI), which is based on the metric system. However, the metric system in not used on an everyday basis in the United States. It is often necessary to convert between the English system, which is used in the United States, and the SI system. One problem with the SI system is the size of the units sometimes turns out to be inconveniently large or small. Therefore it is often necessary to make conversions within the SI system. For this reason, SI units are modified through the use of prefixes when they refer to either larger or smaller quantities. In Europe, gasoline efficiency is measured in km/L. If your car's gas mileage is 40.0 mi/gal, how many liters of gasoline would you need to buy to complete a 142-km trip in Europe? Use the following conversions: 1 km = 0.6214 mi and 1 gal = 3.78 L. Express your answer numerically in liters. L While in Europe, if you drive 117 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 32.0 mi/gal ? Assume that 1 euro = 1.26 dollars. Express your answer numerically in dollars.