Part b if this car's gas tank holds 45 l , how many tanks of gas will you use to drive 1800 km ? express your answer using two significant figures.

The consumption rate of the car from previous part was 55 mpg (miles per gallon).We convert this to kilometers per liter.
1km = 06214 miles
1 gallon = 3.788 liters
hence, 55 mpg will be;
                               55× 1/0.6214×1/3.788 = 23.4 km / L
 Thus, its mileage will be 23.4 km/L
For a distance of 1800 km the car will use; 1800/23.4 = 76.923 L
but, we know that the car gas tank holds 45 L
Hence, for a distance of 1800 km the car will use 76.923/ 45= 1.7094 tanks
That will be 1.7 tanks ( two significant figures)