Problem:
Each of the following four large congruent squares is subdivided into combinations of congruent triangles or rectangles and is partially shaded. What percent of the total area is partially shaded?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
The upper left and the lower right squares are each one-fourth shaded, for a total of one-half square. The shaded portions of the upper right and lower left squares make up one-half square. So the total shaded area is one full square, which is of the total area.
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions