Volume of Cone:
1/3 Bh where B is the area of the base
1/3 Bh = 5
Bh = 15
B = 15/h
The cylinder has the same base area as the cone.
Volume of Cylinder:
V = B*h
B = V/h and B = 15/h
The height of the cone and the cylinder are the same.
V/h = 15/h
Volume of Cylinder = 15.