Scores on a semester project are normally distributed with a mean of 500 and a standard deviation of 125. If a recent project is selected at random, what is the probability the student scored 650 or greater on the project?

Consider the bottom most rectangle.

Its length = 5 - 2 = 3 units

Its width = 3 - 1 = 2 units

So, its area = 3(2) = 6 square units.

Consider the middle rectangle.

Its length = 2 - 1 = 1 unit

Its width = 4 - 2 = 2 units

So, its area = 1(2) = 2 square units.

Finally, consider the top rectangle.

Its length = 6 - 1 = 5 units

Its width = 6 - 4 = 2 units

Its area = 5(2) = 10 square units.

Hence, total area = 6 + 2 + 10 = 18 square units. Correct option is C.