Question

At the factory a baseball card is places in every 9th cereal package a football card is placed in every 25th package what is the first package that gets both the baseball and football card

Answer 1

To figure out this question, look for the first number where both 25 and 9 are a factor of. 

25*1 is 25 which isn't a factor of 9, so it won't be 25.
25*2 is 50, which isn't a factor of 9.
75 is not a factor of 9. (you know because you don't get a whole number when you divide 75 into 9.)
100 is not a factor of 9, nor is 125, 150, 175, or 200.

However, 225 is a factor of both 25 and 9. This makes sense because 25*9 is 225. 

This means that the first package with both will be the 225th package.