Brady has 300 baseball cards. of these, 5% are boston red sox cards. one-fifth of brady’s red sox cards are rookie cards. how many red sox rookie cards does brady have?

5% are boston red sox cards

5% of 300, easy, that is 3 times of 5% of 100 or 3 times 5 or 15

1/5 of those are rookie cards

1/5 of 15 is 15/5=3

he has 3 red sox rookie cards

6mm^3 or .6cm^3

      216

      /   \

  36     6

  /   \     /

6     6   6

factor trees are nice.