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प्रश्न
Three persons enter a railway compartment. If there are 5 seats vacant, in how many ways can they take these seats?
पर्याय
60
20
15
125
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उत्तर
60
Three persons can take 5 seats in 5C3 ways. Moreover, 3 persons can sit in \[3!\] ways.
∴ Required number of ways =\[{}^5 C_3 \times 3! = 10 \times 6 = 60\]
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