Let X variable for the prize.
There is possibility of winning nothing, Rs 500,Rs 2000 and Rs 3000.
So, X will take these values.
Since there are 3 third prizes of 500 probability of winning third prize is 3/10000.
1 first prize of 3000 probability of winning third prize is 1/10000.
1 second prize of 2000 probability of winning third prize is 1/10000.