AP EAMCET202021 Sep 2020Morning ShiftMathematicsPermutation and CombinationActual
If ( n+1 r+1 ^ n+1 C_r = n-r+1 m ), then (m= )
Options
- A(r )
- B(r-1 )
- C(r+1 )
- D(1-r )
Correct answer
C. (r+1 )
Step-by-step solution
( aligned & n+1 r+1 ^ n+1 C_r = n-r+1 m & (n+1) ! (r+1) !(n-r) ! (n+1) ! r !(n-r+1) ! = n-r+1 m & n-r+1 r+1 = n-r+1 m m=r+1 aligned ) Hence, option (c) is correct.