In how many ways can live boys and three girls sit in a row such that all boys sit together?
Correct answer: C. 2880
- A. 4800
- B. 5760
- C. 2880
- D. 15000
Explanation
Treat the 5 boys as one block, giving 4 objects to arrange: the boys' block and 3 girls. These objects can be arranged in 4! ways, and the boys can be arranged inside their block in 5! ways, so the total is 4! x 5! = 24 x 120 = 2880 arrangements. The likely trap is 4800, which overcounts the positions of the boys' block.
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