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प्रश्न
A trust has 25 members. How many ways 3 officers can be selected?
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उत्तर
Number of members in the trust = 25
The number of ways of selecting 3 officers from 25 members is
= 25C3
= `(25!)/(3! xx (25 - 3)!)`
= `(25!)/(3! xx 22!)`
= `(25 xx 24 xx 23 xx 22!)/(3! xx 22!)`
= `(25 xx 24 xx 23)/(3 xx 2 xx 1)`
= 25 × 4 × 23
= 2300
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