Answer:
49
Step-by-step explanation:
Given that the coordinates of the point A is (2,7) and the coordinates of the point B is (6,3)
We need to determine the midpoint of A and B
<u>Midpoint of A and B:</u>
The midpoint of A and B can be determined using the formula,

Substituting the points (2,7) and (6,3) in the above formula, we get;

Adding the numerator, we have;

Dividing the terms, we get;

Thus, the midpoint of the points A and B is (4,5)
You might think that the volume of a circle is needed to solve this problem but you can do it in a more simplified manner. First figure out how much water 85 marbles displace.
26-20.9=5.1 liters of water
Now, let us see how much water 200 marbles displace.
85 marble x (200/85) = 5.1 liters x (200/85)
200 marbles = 12 liters
We can find the amount of water needed to fill the tank now.
26-12=14 liters of water
answer: 14 liters of water