Answer : The cost of gasoline for a 420-mile trip is, $19.95
Solution :
As, 20 mile distance covered by 1 gallon of gas
So, 420 mile distance covered by
of gas
Now we have to calculate the cost of gasoline.
As, 1 gallon of gas cost = $0.95
So, 21 gallon of gas cost = 
Therefore, the cost of gasoline for a 420-mile trip is, $19.95
Mixtures can be classified as homogeneous or heterogeneous . Mixtures are composed of substances that are not chemically combined.
Homogeneous mixtures are solutions. The components of a solution are evenly distributed throughout, so that every part of the solution is the same. The components that make up a solution include one or more solutes dissolved in a solvent. Solutes can be solids, liquids, or gases, and solvents can also be solids, liquids or gases.
Brass is an example of a solid/solid solution, saline solution is an example of a solid/liquid solution, diluted ethanol is an example of a liquid/liquid solution. There are many examples of solutions. The components of a solution can be separated by physical means, such as distillation, evaporation, and chromatography, among others.
Chemical properties can only be analyzed by putting the substance through a chemical reaction, such as combustion.
Physical properties can be analyzed without altering the substance chemically. With that in mind:
Boiling point: physical
Density: physical
Ductility: physical
Heat of combustion: chemical