Answer:
11.781 cubic inches (round accordingly)
Explanation:
The formula for the volume of a cone is:

where r is the radius and h is the height.
For our ice cream cone:
d = 3 inches
r = 1.5 inches (the radius is half of the diameter)
h= 5 inches
So all we have to do is plug in our values and solve for the volume:

So our final answer is around 11.8 cubic inches.