Answer:
5/11 x 1/10
Explanation:
5/11 for the blue pencils because there are 11 pencils overall and 5 blue ones.
1/10 for the yellow pencils because once she takes out a blue pencil, there will be 10 pencils overall left and there is 1 yellow pencil.
You multiply because you only add when it says "or" in the question.
Hope this helps :)