If `^(m+n)P_2=90 and ^(m-n)P_2=30` find m and n

If .^(m+n)P_(2)=90 and .^(m-n)P_(2)=30 , find the value of m and .

(m+n)P_(2)=56,^(m-n)P_(2)=30 then

if .^(m+n)P_(2)=56 and .^(m-n)P_(3)=24 , then (.^(m)P_(3))/(.^(n)P_(2)) equals

If m and n are +ve integers such that (m+n)P_(2)=90 and m-np_(2)=30, the number of ordered pairs (m,n) of such integers is