SOLUTION
Let us sketch the composite figure of the floor plan
We are have now divided the floor plan into two sections which consist of two rectangles.
Let us now solve for the area of the floor-plan
The formula for the area of a rectangle is,
Therefore, the area of section A is,
Given
Hence,
Also, the area of section B is
Given
Hence,
Therefore, the amount of the tile needed to cover the floor is the sum of the area of section A and the area section B is
Hence, the answer is 680ft² (OPTION A).