If p>q, the number of ways of p men and q women can be seated in a row so that no two women sit together is
If p+1qp-qp-1qp+qq+1pp-qq-1pp+q=pqx, then x =_________.
A body P strikes another body Q of mass that is p times that of body P and moving with a velocity that is 1q of the velocity of body P. If body P comes to rest, the coefficient of restitution is