Final answer:
The IQ of the 8-year-old child with a mental age of 6 years is calculated to be 75 using the formula IQ = (Mental Age / Chronological Age) × 100.
Step-by-step explanation:
The intelligence quotient (IQ) of a child is calculated by the formula:
IQ = (Mental Age / Chronological Age) × 100. Applying this formula to the provided case where an 8-year-old child has a mental age of 6 years gives us:
IQ = (6 / 8) × 100 = 0.75 × 100 = 75.
Therefore, for school placement purposes, the intelligence quotient (IQ) should be reported as 75, which is option B.