From
Maths is funOur Solution:
2/3
You know that you do not have Bag B (two black marbles) so there are three possibilities
You chose Bag A, first white marble. The other marble will be white
You chose Bag A, second white marble. The other marble will be white
You chose Bag C, the white marble. The other marble will be black
So 2 out of 3 possibilities are white.