I believe it would be 12/18 so that would be 2/3 and 0.6 in decimal form
1. -1, 2,8,11
plug the values into the equation and solve
Answer:

Step-by-step explanation:
the volume of a cylinder is given by:

and the volume of a cone is given by:

since both have the same height and radius, we can solve each equation for
(because this quantity is the same in both figures) and then match the expressions we find:
from the cylinder's volume formula:

and from the cone's volume formula:

matching the two previous expressions:

we solve for the volume of a cone
:

substituting the value of the cylinder's volume 

X can be -1 or 1 for the square root to be 0
The correct option is a