year abroad placement

Hi there!! I have a question regarding my work placement for my year abroad. I want to work for this charity but they only offer a two month internship, however I have to complete a minimum of three months of work for my placement. There is a teaching assistant role which I am also in the process of confirming which would be for the three months, but I wanted to see whether I could arrange to do two months with the charity first and then one month as a teaching assistant to complete the three months. I don know if this is possible, so I wanted to know whether it is possible to do two work placements?
any help would be really appreciated!!!