At an art exhibition, there were 280 men and 450 women in Hall A. In Hall B, there were 220 men and 665 women. Some men moved from Hall A to Hall B and some women moved from Hall B to Hall A such that 20% of the people in Hall A and 50% of the people in Hall B are men. How many people are there in Hall B in the end?
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I don't know much about art.... but I know what I like...
dogs playing poker...
dogs playing pool...
Can't come up with any elegant way to do the question, so we'll just have to stick with good old "take this to be x and that to be y" method.
Let the men who moved to hall B be x.
Let the women who moved to hall A be y.
Now, the population of the rooms is something like,
Hall A: 280-x men and 450+y women
Hall B: 220+x men and 665-y women
Data given: 20% of Hall A are men.
50% of Hall B are women.
Each point of data gives one equation in x and y. You get two equations. Solve them and you should be able to find the number of people in Hall B.