The IQ of person is given by the formula, IQ = m/c x 100, where m is the mental age and c is the chronological age. If 80 ≤ IQ ≤ 140 for a group of 12-year children, find the range of their mental age.

By BYJU'S Exam Prep

Updated on: September 25th, 2023

The range of their mental age is 9.6 years or more and 16.8 years or less.

Given that:

When c = 12, we have IQ = m/12 x 100 = 25m/ 3

It is also given that:

80 ≤ IQ ≤ 140

By substituting the value of IQ we get:

80 ≤ 25m/3 ≤ 140

80 ≤ 25m/3 and 25m/3 ≤ 140

3/25 x 80 ≤ m and m ≤ 140 x 3/25

48/5 ≤ m and m ≤ 84/5

9.6 ≤ m ≤ 16.8

The needed mental age is therefore 9.6 years or greater and 16.8 years or less for a group of 12-year-old youngsters.

Table of content

1. The IQ of person is given by the formula, IQ = m/c x 100, where m is the mental age and c is the chronological age. If 80 ≤ IQ ≤ 140 for a group of 12-year children, find the range of their mental age.

Mental Age

Mental age is the age, as measured by an intelligence test, at which a specific level of performance is considered average or usual.
An individual’s intelligence quotient is calculated by first dividing his mental age by his chronological age and multiplying the result by 100.
(IQ). As a result, a person with the same mental and chronological ages has an IQ of 100 or average intelligence.
Alfred Binet, a French psychologist who developed the intelligence test in 1905, was the first to define mental age.
Mental ages can’t be used to compare children of different chronological ages’ fundamental abilities because the variation in scores for different age groups taking graded tests rises roughly proportionately to the increase in age.

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