The number of values of r satisfying the equation 69 C 3r−1 ​ − 69 C r 2 ​ = 69 C r 2 −1 ​ − 69 C 3r ​ is:

The number of values of 'r' satisfying the equation ""^(39)C_(3r-1)- ""^(39)C_(r^(2) )= ""^(39)C_(r^(2)-1) - ""^(39)C_(3r) is

Find the value (s) of r satisfying the equation "^69 C_(3r-1)-^(69)C_(r^2)=^(69)C_(r^2-1)-^(69)C_(3r)dot

The value of (b-c)/r_1+ (c-a)/r_2+ (a-b)/r_3 is equal to

The number of values in set of values of r for which ^23 C_r+2.^(23)C_(r+1)+^(23)C_(r+2)geq^(25)C_(15) is

In any triangle, the minimum value of r_1r_2r_3//r^3 is equal to (a) 1 (b) 9 (c) 27 (d) none of these

In a triangle ABC, ab and c are the sides of the triangle satisfying the relation r_(1)+r_(2) = r_(3)-r then the perimeter of the triangle

If ""^(n)C _r denotes the numbers of combinations of n things taken r at a time, then the expression ""^(n) C_(r+1) +""^(n)C_(r-1) +2 xx ""^(n)C_r equals

Prove the questions a(r r_(1) + r_(2)r_(3)) = b(r r_(2) + r_(3) r_(1)) = c (r r_(3) + r_(1) r_(2))

If n is a positive integer and C_r = ""^nC_r then find the value of sum_(x = 1)^n r^2 ((C_r)/(C_(r - 1)) )

A 3xx3 matrix A, with 1st row elements as 2,-1,-1 respectively, is modified as below to get another matrix B. R_1 elements of A go to R_3 of matrix C R_2 elements of A go to R_1 of matrix C R_2 elements of A to R_1 of matrix C R_3 elements of A go to R_2 fo matrix C Now, below operations are done on C as follow, C_1 elements of C go to C_3 of B C_2 elements of C go to C_1 of B C_3 elements of C go to C_2 of B It is found that A = B, then