Answer:
11/20
Step-by-step explanation:
At the beginning, the number of marbles in the box are:
10 green marbles
11 white marbles
The first marble chosen is green, and then it is not replaced in the box. Therefore, the number of green marbles left in the box is 9.
Therefore, the total number of marbles left in the box is:
Now we want to find the probability to choose a white marble. The number of white marble is
Therefore, the probability of choosing a white marble is: