First you have to find 1/3 of the marbles. That means in the twelve marvels she has, there are three even groups. Divide twelve by three and you get four. So if each group is four, it is simple from here on out. If she started out with twelve and she lost 1/3 of them(4) it would be 12-4. You know this because lost is another for for subtract. 12-4=8. She has 8 marbles left.
If I could see the photo I could help you answer the question
