If a fruit cake needs 3 4 of a carton of all-purpose cream and 2 3 of a carton of condensed milk to make, how many cartons of all purpose cream does Grandma need to buy to make 5 fruit cakes?

3/4 * 5= 3 3/4 cartons. You can’t buy 3/4 of a carton so Grandma would need to buy 4 cartons of all-purpose cream.

2/3 * 5= 3 1/3. But you can’t buy 1/3 of a carton, so grandma needs to buy 4 cartons of condensed milk.

All together, Grandma needs to buy 4 cartons of all-purpose cream and 4 cartons of condensed milk to make 5 fruit cakes.