Using the IQ formula, if mental age is 12 and chronological age is 10, IQ equals 120.

Using the IQ formula, if mental age is 12 and chronological age is 10, IQ equals 120.

• A. 112
• B. 100
• C. 150
• D. 120

Answer: (D)

IQ is calculated by multiplying the ratio of mental age to chronological age by 100. With a mental age of 12 and a chronological age of 10, you do 12 ÷ 10 = 1.2, then 1.2 × 100 = 120. This means the individual’s performance aligns with the level typical of someone older, resulting in an above-average IQ. The other numbers don’t fit the given ages: 100 would require equal ages (12 ÷ 12 or 10 ÷ 10), 150 would need a mental age of 15 at age 10, and 112 would come from a different mental-to-chronic age ratio. Thus, the correct result is 120.

IQ is calculated by multiplying the ratio of mental age to chronological age by 100. With a mental age of 12 and a chronological age of 10, you do 12 ÷ 10 = 1.2, then 1.2 × 100 = 120. This means the individual’s performance aligns with the level typical of someone older, resulting in an above-average IQ. The other numbers don’t fit the given ages: 100 would require equal ages (12 ÷ 12 or 10 ÷ 10), 150 would need a mental age of 15 at age 10, and 112 would come from a different mental-to-chronic age ratio. Thus, the correct result is 120.