She will plant again in 2 days and trim them again in 15 days.
That would be my guess.
How sad, that you didn't include the list of choices.
The volume of the cone is (1/3) x (π) x (radius²) .
The volume of the sphere is (4/3) x (π) x (radius³) .
8th grader here, what do you need help with?
