Ralphie is taking a ten-question multiple choice test. Each question has five choices. If Ralphie answers a question correctly.
he earns one point; if he answers it incorrectly, he loses a quarter of a point. Ralphie answers the first seven questions
correctly, then guesses on the last three. What is the expected value of his test score? Round the answer to the nearest
whole percent.
A 0%
B. 529
C. 68%
D. 70%