I just answered this xD
1-3 is given as an example.
4. True
5. False. It is the same thing twice
6. True
You could make the numbers have a common denominator.
-3/7 --> -9/21
-2/3 --> -14/21
|-14/21| - |-9/21| = 5/21 difference.
5/21 is the distance.
First take the inside diameter and divide by 2 to get the radius (4cm)
Then use

r^2 with 'r' being your radius to get the area of the base
The area is 12.7 cm
Now multiply the height by the area of the base to get the volume/ capacity!
40cm x 12.7cm (rounded to the nearest tenth) = 502.7 cubic centimeters