The probability of picking an even numbered domino is {number of even numbered dominoes}/{total number of dominoes}. This means that 3/4 = 48/{total number of dominoes}. You divide both sides by 48 and get : 1/64 = 1/{total number of dominoes}. You find the reciprocal of both sides, and get: 64 = {total number of dominoes}
When comparing two things make sure to put what the question says first, first. Add the number of soccer and softball players that got awards to find the total number of award winners.