Those who won the first and second prizes accounted for three-fifths of the total winners, that is, those who won the third prize accounted for two-fifths of the total winners.
14/ 15 of the total number of winners won the second and third prizes, that is,115 of the total number of winners won the first prize.
Therefore,1-115-2/5 = 8/15 of the total number of winners who won the second prize.