5. A lattice path from (x0, y0) to
in the ay plane is defined as a sequence of points (x0, y0), (x1,y1), ,
such that each
and each,
± 1,i =1,2, n - 1. How many lattices paths are there from (0,1) to (10,3)? How many of them do not touch or cross the t axis?