No. of cars / Population = Cars per person
1) Let population be x . here, 5.3 / 0.32 = 16.56
2) Let no. of cars be x. here, x / 18.3 = 0.5 thus, x=9.15 approx 9.2
3) Serbistan
4) If cars per person = 0.7556 population = 9.2M then no. of cars = 9.2 * 0.7556 = 6.95 M