The number of distinct rational numbers of the form p/q, where p,q ϵ {1,2,3,4,5,6} is
p=1,q=1,2,3,4,5,6⇒6p=2,q=1,3,4,5,6⇒3[∵(2,4),(2,6)]p=3,q=1,2,4,5,6⇒4[∵(3,6)]p=4,q=1,3,5,6⇒3[∵(4,6)]p=5,q=1,2,3,4,6⇒5p=6,q=1,5⇒2