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Number of ways in which three numbers in A.P. can be selected from `1,2,3,..., n` is a. `((n-1)/2)^2` if `n` is even b. `((n-2)/4)^` if `n` is even c. `((n-1)/4)^2` if `n` is odd d. none of these

A

`((n-2)(n-4))/(4)`, if n is even

B

`(n^(2)-4n+5)/(2)`, if n is odd

C

`((n-1)^(2))/(4), ` if n is odd

D

`(n(n-2))/(4)`, if n is even

Text Solution

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The correct Answer is:
C, D
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