Allison has 5 times as many baseball cards as football cards. in all, she has 120 baseball and football cards. how many baseball cards does she have?

If Allison has x football cards she will have 5x baseball cards. 
So x + 5x = 120 
6x = 120 
x = 120/6 = 20 
Allison 5x baseball cards so 20*5 = 100 baseball cards