Answer:
36/121
Step-by-step explanation:
Probability is a relation between the amount of appropriate results and the total amount of results.
The total amount of the marbles is 6+5=11
We must take only blue marbles so the amount of appropriate results is 6.
The probability of taking blue marble in the 1st turn is 6/11. Then we put the marble back so the amount of marbles doesn't change. That's why the probability of taking blue marble in the 2nd turn is also 6/11.
But we have to count the probability of taking blue marble in both cases. To do it we must multiply the probability of taking blue marble in the 1st turn and the probability of taking blue marble in the 2nd turn.
(6/11)*(6/11)=36/121
