Let $P_k$ represent the perimeter of a square with sides of length $k$. The value of the expression $P_1+P_2+P_3+\ldots+P_{10}$ is $\_\_\_\_$ .

The city of Atlantis was crafted by the God of the seas, Poseidon. It was made of alternating concentric circular rings of land (shaded) and water (not shaded) as represented in the figure (not to scale). The radius of Inner Island was 2.5 stades (a unit of length used in ancient Greece). The water surrounding Inner Island was one stade wide (length AB ). This was surrounded by two pairs of alternating rings of land and water. The first pair of land and water was two stades wide each (lengths BC and CD), and the outer pair is three stades wide each (lengths DE and EF).

The ratio of the surface area of the land to that of the water in the city of Atlantis is

$\_\_\_\_$ (round off to two decimal places).