High School

A 10-year-old takes an IQ test and answers the questions of a 9-year-old. What would be his IQ?

A. 90
B. 100
C. 110
D. 120

Answer :

Final answer:

To calculate the IQ score of a 10-year-old answering at a 9-year-old level, you divide the mental age (9) by chronological age (10), and then multiply by 100, resulting in an IQ score of A) 90.

Explanation:

The question asked is regarding the calculation of IQ score for a child. IQ, which stands for Intelligence Quotient, is a measure of a person's mental agility relative to their age group. To calculate IQ, the formula commonly used is (mental age/chronological age) x 100. In this scenario, a 10-year-old child is answering the questions of a 9-year-old level.

To calculate the child's IQ:

  1. First, you determine the child's mental age, which in this case is 9 years.
  2. Next, you divide the mental age by the child's actual chronological age, which is 10. So, 9/10 equals 0.9.
  3. Finally, you multiply the result by 100 to get the IQ score: 0.9 x 100 = 90.

Therefore, the correct answer to the student's question is A. 90.