If ^nP_r=^nC_r x`,then x=?

if ^nP_r= ^nP_(r+1) and ^nC_r= ^nC_(r-1) find n and r.

If .^nP_r=504 , .^nC_r=84 find n and r.

If .^nC_x=^nC_y and x ne y ,then x+y=? .

Find the values of n and r if ""^nP_r=336,""^nC_r=56 .

For which values of r, .^nC_r=^nP_r ?

A boy instead of writing .^nP_r writes .^nC_r By what number should he multiply his result to get the correct answer?

Show that ^nC_r+2. ^nC_(r-1)+ ^nC_(r-2)= ^(n+2)C_r

Write the relation between ^nP_r and ^nC_r

Prove that .^(n-1)P_r+r.^(n-1)P_(r-1)=^nP_r .

Prove that .^(n+1)C_(r+1)+^nC_r+^nC_(r-1)=^(n+2)C_(r+1)