11 and 11/15 is the answer
11 liters of 25% orange juice, 4 liters of 10% orange juice:
1' let x to be 25% orange juice and y be 10% orange juice
2' .25x+.10y=(15).21
3' x+y=15
4' 2.5x+y=31.5 divide all sides by 10
5' -x-y=-15 multiply all sides by -1
6' 1.5x=16.5
7' x=11
8' y=15-11=4
so 11 and 4 are the answers.
The square root of 71 is equal to 8.426149773176359...., which is between 8 and 9.
To check: square of 8 is 64, and of 9 is 81: 71 is between those two numbers, as it should be.
From the Venn diagram, we can gather that there are 35 total objects (6 in both A and B; 15 in A but not B; 10 in B but not A; and 4 in neither A nor B), and we have the probabilities
(this is the answer)
By definition of conditional probability,
