Demetrius, a 10-year-old, is taking the original Stanford-Binet intelligence test. If he consistently answers questions correctly at the level of a 12-year-old, then according to Wilhelm Stern's original scoring method, Demetrius's intelligence quotient is:

a. 100.

b. 120.

c. 80.

d. 110.

Answer is B. 120

Refer below.

Explanation:

Demetrius, a 10-year-old, is taking the original Stanford-Binet intelligence test. If he consistently answers questions correctly at the level of a 12-year-old, then according to Wilhelm Stern's original scoring method, Demetrius's intelligence quotient is:

120

b. 120.

Explanation:

Intelligence test is defined as a psychological test that is prepared to determine the mental capacity to make abstractions, to learn, and to deal with novel situations.

In other words, it is a test that is desgined to measure level of intelligence.

Scores may be presented as an IQ (intelligence quotient), as a mental age, or on a scale.

Hence, Wechsler intelligence tests which was developed by a clinical psychologist David Wechsler are a widely used series of intelligence tests, designed to examine specific and overall cognitive capabilities and is individually administered to young kids, adolescents and adults between ages 6-89.

Hence, the IQ was originally calculated as the ratio of a person's mental age to his chronological (physical) age, multiplied by 100.

In this case, Demetrius age is 10 years, and has a mental age of 12years (this means that, he performed on the test at the level of an average 12-year-old), then the IQ is measured as 12/10 * 100 = 120

Hence, answer is 120.