<prompt> IQ in moderate mental retardation -90-7070-5050-3535-20  <response>: WHO classification of Mental retardationMR mild MR...IQ 50-70 moderate MR ...35-49 severe MR..IQ 20-34 profound MR...IQ under 20 ref; page no;582 23rd edition of PARK;s textbook of Preventive and Social medicine 