If `.^(n-1)C_r:^nC_r:^(n+1)C_r=6:9:13` find n and r.

If .^(n+1)C_(r+1.): ^nC_r: ^(n-1)C_(r-1)=11:6:3 find the values of n and r.

If .^(n+1)C_(r+1):^(n)C_(r):^(n-1)C_(r-1)=11:6:3 , find the values of n and r.

If .^(n)C_(r-1)=36, .^(n)C_(r)=84 and .^(n)C_(r+1)=126 , find n and r.

If .^(n+1)C_(r+1):^n C_r:^(n-1)C_(r-1)=11 :6:3, then n r= 20 b. 30 c. 40 d. 50

If .^(n+1)C_(r+1) :^n C_r :^(n-1)C_(r-1)=11 :6:3, then n r=? a. 20 b. 30 c. 40 d. 50

If .^(n)C_(r-1): .^(n)C_(r): .^(n)C_(r+1)=3:4:5 , find the values of n and r.

The roots of the equation |^x C_r^(n-1)C_r^(n-1)C_(r-1)^(x+1)C_r^n C_r^n C_(r-1)^(x+2)C_r^(n+1)C_r^(n+1)C_(r-1)|=0 are a) x=n b) x=n+1 c) x=n-1 d) x=n-2

The value of sum_(r=0)^(n-1)^n C_r//(^n C_r+^n C_(r+1)) equals a. n+1 b. n//2 c. n+2 d. none of these

If ""^(n)C_r : ""^(n)C_(r+1) =1 : 2 and^(n)C_(r+1): ""^(n)C_(r+2) = 2 : 3 determine the values of n and r.

If sum_(r=0)^(n-1)(("^nC_r)/(^nC_r+^nC_(r+1)))^3=4/5 then n=