Mark and Ali have 604 cards altogether. 1/3 of Mark’s cards is 28 more than 1/5 of Ali’s cards. How many cards does Ali have?
Ali's number --- x
Mark's number = 604-x
(1/3)(604 - x) - (1/5)x = 28
times 15, the LCD
5(604-x) - 3x = 420
3020 - 5x - 3x = 420
-8x = -2600
x = 325
Alis has 325 cards, (Mark has 279)