​​ Solve:

Q. Find the numerical value of P.Q, where, 
               $P = {\left(\frac{x^m}{x^n}\right)}^{m+n -1} x {\left(\frac{x^n}{x^l}\right)}^{n+l-m} x{\left(\frac{x^l}{x^m}\right)}^{l+m-n} and Q ={\left(\frac{1}{x^{a-b}}\right)}^{\frac{1}{a-c}} x{\left(\frac{1}{x^{b-c}}\right)}^{\frac{1}{b-a}} x{\left(\frac{1}{x^{c-a}}\right)}^{\frac{1}{c-b}}$ where a, b, c are all different.