The Pennsylvania Daily Number is a three-digit number game that costs $1 per “number” and has a winning ticket payoff of $500. On April 24, 1980, the winning number was 666. Several weeks later it was discovered that the April 24 drawing had been fixed. Exposure of the scandal revealed that all balls except those with 4 or 6 had been altered so that the winning number would contain only those digits. If you purchased a $1 ticket for each possible 3-digit number that consisted of only 4s or 6s, find the expected payoff on:

(a) April 24, 1980. (First list all possible 3-digit numbers that consist of only 4s or 6s.)

(b) A day when the lottery was not fixed.