Using the original calculation of IQ scores, a 12-year-old girl with an IQ of 50 has a mental age of _______ years.
A) 6
B) 8
C) 12
D) 14

Question

Quizplus · Accepted Answer

The original formula for IQ scores was based on the concept of "mental age", or the average intellectual abilities of a certain age group. A score of 100 meant that the individual had an average mental age for their chronological age. In this case, a 12-year-old girl with an IQ of 50 would have a mental age of 6, calculated as follows: 
Mental Age = (IQ/100) x Chronological Age
Mental Age = (50/100) x 12
Mental Age = 0.5 x 12
Mental Age = 6

Using the Original Calculation of IQ Scores, a 12-Year-Old Girl