Question: An apartment building has 12 floors and half of them are full. The remaining floors are all at half-capacity. If each floor has 10 apartments and each apartment has four people, how many people are in the building? Think carefully first, then make a decision:
Half the floors are full, so there are 12 floors * 0.5 = 6 floors that are full. So the full floors contain 6 floors * 10 apartments = 60 apartments. The remaining floors are at half - capacity, so there are 12 floors – 6 full floors = 6 half - full floors. Each of these floors therefore contains 10 apartments * 0.5 = 5 apartments. So on the half - full floors, there are a total of 6 floors * 5 apartments = 30 apartments. In total, there are 30 + 60 = 90 filled apartments in the building. This means there are 90 apartments * 4 people per apartment = 360 people in the building. So the answer is 360.