This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Growth and Development, Subject name: Social & Preventive Medicine
A child of 10 years has a mental age of 2 years, his IQ level is:- 
Select and explain. 
A. 20 IQ points, B. 30 IQ points, C. 50 IQ points, D. 70 IQ points
A: 20 IQ points
Answer: A: 20 IQ points 
Explanation: IQ = Mental age /Chronological age x 100 In the given question, chronological age is 10 years and mental age is 2 years. Thus, IQ level of this child= 2/10 x100=20 IQ points. Such a child will be an Idiot child with Severe mental retardation. Normal IQ 70 or above Mild mental retardation = 50-70 Moderate mental retardation = 35-49 Severe mental retardation = 20-34 Profound mental retardation = <20