Question 62765
Clearly sample space S = {1,2,3,4 5,.....18}

Let E = event of stopping at an even number or a multiple of 3.

      = {2,3,4,6,8,9,10,12,14,15,16,18}

So n(S) = 18 and n(E) = 12

Therefore P(stopping at an even number or a multiple of 3) = P(E)

                                                  = n(E)/n(S)

                                                  = 12/18

                                                  = 2/3

Hence the required probability = 2/3


Good Luck!!!