A decade ago there were more than 200 days of horseracing each year at Fairmount Park. These days there are 60. With the deals the track is trotting out, it's hard to fathom why people aren't flocking to play the ponies. Take Fairmount's Horse Hooky Tuesdays, which promise a full afternoon of thoroughbred racing for the cheap admission price of $1.50. Not only is the crowd more colorful on Tuesday at 1:30 p.m. (crusty, cigar-chomping old men and Mexican cowboys, mostly) but with $2 bottles of Coors and 75-cent hot dogs, you can get a belly full of beer and hot food for less than a two-horse exacta box. Of course, if you also play that exacta box, you stand a chance of walking out with more than you came in with.