When 0.2 kg of gasoline undergoes combustion, 18500 kJ of energy are released. Express the heat released, 18500 kJ in calories. (Given 4.184 J = 1 cal)

The problem above is simply asking to convert one unit of energy to another of unit energy. We convert measurements by multiplying conversion factors. The conversion factor, for this case, is 1 cal / 4.184 kJ. We multiply this value to the measurement.

18500 kJ (1/4.184) = 4421.61 calories