Answer the following questions.
(1) How many ways of route from A to B is there in lower Fig. 1?
Noted that there are right or down directions of moving.
(2) How many ways of route from A to B is there in lower Fig. 2?
Noted that there are right or down or lower right directions of moving.
(3) How many ways of route from A to B with passing along neither P nor Q is there in lower Fig. 3?
Noted that there are right or down or lower right directions of moving.
