If we assume all thirty 4-wheel drive cars in the parking lot have their spare tire with them, how many tires are in the parking lot? Let's answer step by step:
Each car has 4 tires + 1 spare = 5 tires. If there are 30 cars in the parking lot and each one has 5 tires, then the total number of tires is 30 * 5 = 150 tires. The answer: 150.