Answer :
Marcus must play 18 arcade games to earn enough tickets for the prize he wants.
Marcus needs 550 tickets for a prize and already has 125 tickets. Each arcade game he plays earns him 24 tickets. To find out how many games Marcus will need to play, we subtract the tickets he already has from the total required tickets and then divide by the number of tickets earned per game. The calculation is as follows:
550 tickets needed - 125 tickets already = 425 tickets needed from playing games
Then we divide:
425 tickets needed / 24 tickets per game = 17.7083 games
Since Marcus cannot play a fraction of a game, he must play 18 games to earn enough tickets for the prize.