You are asked to derive the IQ score for one of your friends. If you were using Terman's notion of an IQ, you would

a. add mental age to chronological age and divide the result by 100.
b. add 110 to mental age and then divide the result by chronological age.
c. divide mental age by chronological age and multiply the result by 100.
d. add chronological age to mental age and multiply the result by 100.

Answer: c. divide mental age by chronological age and multiply the result by 100.