r ज्ञात कीजिए यदि `P(10,r+1):P(11,r)=30:11`.

If P(10, k+1): P(11, k) = 30 : 11, then

Find r if : ^10P_(r+1): "^11 P_(r)= 30:11 .

Find r if : P(11,r) = P(12,r-1)

If P(11,r)=P(12,r-1) find n

Find 'r' if : (i) ""^(5)P_(r )= ""^(6)P_(r-1) (ii) 5""^(4)P_(r )=6""^(5)P_(r-1) (iii) ""^(5)P_(r )=2""^(6)P_(r-1) (iv) ""^(10)P_(r+1): ""^(11)P_(r )=30 :11 .

Compute P for n=11,r=0

If P(12,r)=P(11,6)+6.P(11,5) then r=

Find r, if "^(12)P_(r-2) : ^(11)P_(r-1) = 3:14

If P(11 , r)=P(12 , r-1) find ndot