Find r, if `5^4P_r=6^5P_(r-1)`.

Find r, if 5^(4)P_(r)=6^(5)P_(r-1)

Find r if (i) ^5P_r=2""""^6P_(r-1) (ii) ^5P_r=^6P_(r-1)

Find r if 4.P(6,r)=P(6,r+1)

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 .

Find r when P(4,r)=6P(5,r-1)

Find r if (i) .^(5)P_(r) = 2 .^(6)P_(r-1) (ii) .^(5)P_(r) =^(6)P_(r-1) .

Find the value of 'r' if ""^(5)P_(r )=""^(6)P_(r-1) .