Question

In my stamp collection I have 10 red and 9 green stamps. I have 9 from Canada and 10 from Japan. I have 1 pink stamp that is not from either Canada or Japan. 3 of my Canada stamps are red and 2 are green. 3 of my Japanese stamps are green and 4 are red. What is the smallest number of stamps I could have in my collection?

Answer 1

27 Stamps

Explanation:

If we add up all the stamps:

10 Red + 9 Green + 9 (Canada) + 10 (Japan) + 1 Pink stamp + 3 (RC) + 2 (GC) + 3 (GJ) + 4 (RJ) = 39 Stamps

So 39 stamps are our maximum amount of stamps. If we think about it, we realize that Canada and Japan have stamps that double the amount of our final sum unnecessarily. I.E. those that are underlined in the solution. If we subtract those from our sum of 39 we then get 27

So the smallest amount of stamps you could have in your collection is 27 Stamps.

I hope this helps Gab :)

Answer 2

You have 3 red Canadian stamps and 2 green Canadian stamps the smallest number of the stamps is the Canadian stamps