Question

half of your baseball cards collection got wet and was ruined. you bought 19 cards to replace some that were lost. how many did you begin with if you now have 45.

Answer 1

38 cards

Explanation:

Assuming that you replaced all your baseball cards that were ruined, that would mean that you started with 38, because we know that 19 is half of all the baseball cards that were lost so 19*2=38

Answer 2

52 baseball cards.
45-19=26
26*2=52