" If "C(28,2r)=C(28,2r-4)," then what is requal to ? "

If C(28, 2r)=C(28, 2r-4) , then what is r equal to ?

If 28C_(2r):24C_(2r-4)=225:11, then the value of r is

If the mode of 2.5, 2.7, 2.8, 2.7, 2.5, x , 2.8, 2.7, 2.8 is 2.8, then what is the value of x?

Given that C(n, r) : C(n,r + 1) = 1 : 2 and C(n,r + 1) : C(n,r + 2) = 2 : 3 . What is r equal to ?

If "^(n)C_(0)-^(n)C_(1)+^(n)C_(2)-^(n)C_(3)+...+(-1)^(r )*^(n)C_(r )=28 , then n is equal to ……

If "^(n)C_(0)-^(n)C_(1)+^(n)C_(2)-^(n)C_(3)+...+(-1)^(r )*^(n)C_(r )=28 , then n is equal to ……

If "^(n)C_(0)-^(n)C_(1)+^(n)C_(2)-^(n)C_(3)+...+(-1)^(r )*^(n)C_(r )=28 , then n is equal to ……

If .^(n)C_(r - 1) = 28, .^(n)C_(r) = 56 and .^(n)C_(r + 1) = 70 , then the value of r is equal to

If the value of the sum 29(.^(30)C_(0))+28(.^(30)C_(1))+27(.^(30)C_(2))+…….+1(.^(30)C_(28))-(.^(30)C_(30)) is equal to K.2^(32) , then the value of K is equal to