In a building, there are a hundred ladies on the first-floor studying. There are three times that many girls at a party being held on the second floor of the building. How many ladies are on the two floors in total? Let's think first. Chain of thought:
If there are a hundred ladies in the living room and three times that many girls at the party, there are 3 * 100 = 300 girls at the party. In the building there are 100 + 300 = 400 ladies.
Therefore, the answer is 400.