On the Stanford-Binet Intelligence Scale, Susan Answered Fewer Items Correctly

Multiple Choice

On the Stanford-Binet Intelligence Scale, Susan answered fewer items correctly than her friend Keri. Yet, Susan's IQ score was higher than Keri's. How can this be possible?

A) Susan is older than Keri.
B) Susan is younger than Keri.
C) Susan and Keri are the same age.
D) None of these.