The reading corner's floor is shaped like a rectangle. The floor measures 15 meters in length and 6 meters in width. This is 90 sq m in total. Floor tiles are sold in packages that cover different areas:

a small pack covers 5 square meters,

a medium pack covers 20 square meters, and

a large pack covers 50 square meters.

Which packs and how many should she buy to cover the area of the reading corner?