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if .^(2n)C(2):^(n)C(2)=9:2 and .^(n)C(r)...

if `.^(2n)C_(2):^(n)C_(2)=9:2 and .^(n)C_(r)=10`, then r is equal to

A

2

B

3

C

4

D

5

Text Solution

Verified by Experts

The correct Answer is:
A
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