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A guard of 12 men is formed from a group...

A guard of `12` men is formed from a group of `n` soldiers. It is found that `2` particular soldiers `A` and `B` are `3` times as often together on guard as `3` particular soldiers `C, D` & `E`. Then `n` is equal to

A

`28`

B

`27`

C

`32`

D

`36`

Text Solution

Verified by Experts

The correct Answer is:
C
`(c )` `.^(n-2)C_(12-2)=3.^(n-3)C_(12-3)`
`implies.^(n-2)C_(10)=3.^(n-3)C_(9)`
`implies(n-2)/(10)=3impliesn=32`
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