A child of 16 years scores 75 in an IQ test. What will be his mental age (in…

Intelligence Quotient (IQ) measures mental development relative to chronological age using the formula IQ = (Mental Age ÷ Chronological Age) × 100, where Mental Age (MA) is a person's demonstrated level of intellectual development and Chronological Age (CA) is their actual age in years.

1. Write the IQ formula: IQ = (MA ÷ CA) × 100.

2. Substitute the given values: IQ = 75 and CA = 16 years.

3. Rearrange to isolate Mental Age: MA = (IQ × CA) ÷ 100.

4. Compute: MA = (75 × 16) ÷ 100 = 1200 ÷ 100 = 12 years.

Substituting MA = 12 back into the formula gives IQ = (12 ÷ 16) × 100 = 75, which matches the given IQ score, confirming the result.

Hence, the child's mental age is 12 years.