If `6C_6 + 7C_6 + 8C_6 +.....+ 13C_6 = mC_r` (where `m < 20`) then the value of `(m-r)` is equal to

If "^6C_(m 2)("6^C_(m+1))+"6C_(m+2)="^8C_3 (where m ne 1 ) & "^(n+1)P_3 / "^nP_4 = 1/8 , then value of "^(n+1)C_m "nP_m is

If (n-1) C_6 + (n-1)C_7 > nC_6 then

"^14C_5 + "^14C_6 + "^15C_7 + "^16C_8 = "^17C_r , then r =

Find the sum C_0-C_2+C_4-C_6+ ......... ,where C_r=^n C_r .

Find the sum C_0-C_2+C_4-C_6+ ......... ,where C_r=^n C_r .

Find r if ^(11)C_4 + ^(11)C_5 + ^(12)C_6 + ^(13)C_7 = ^(14)C_r

(""^(8) C_(0) )/(6) - ""^(8) C_1 + ""^(8) C_(2) . 6-""^(8) C_3 . 6^2 + ... + ""^(8) C_(8) .6^(7) is equal to (i) 0 (ii) 6^7 (iii) 6^5 (iv) (5^8)/(6)

In a parallelogram A B C D diagonals A C and B D intersect at O and A C=6. 8c m and B D=13. 6c m . Find the measures of O C and O D .

Find the sum C_(0)-C_(2)+C_(4)-C_(6)+........ Where C_(r)=nC_(r)

Construct a quadrilateral A B C D in which A B=7. 7 c m ,\ B C=6. 8 c m ,\ C D=5. 1 c m ,\ A D=3. 6 c m\ a n d\ /_C=120^0dot