Ben has a collection of 240 baseball cards. Of these cards, 30% once played for the Atlanta Braves, 25% once played for the Texas Rangers, and the rest
played for the Houston Astros. How many of the baseball cards were
players from the Houston Astros?

Ok so lets start off with calculating the percentage. We have 240 cards so lets find 25% of them so lets use 240 times .25 we get 60 cards then take away 240 - 60 = 180. Next we do the 30% so 240 times .30 would be 72 so take away 180 from 72 thats 108. So there are 108 Houston Astros Cards.