<prompt> A person is said to be mentally retarded when IQ is-100908070  <response>: Ans. is d i.e., 70 o Normal IQ- 90-109;o Borderline IQ- 70-89;o Mild mental retardation IQ- 50-69;o Moderate mental retardation IQ- 35-49;o Severe MR IQ- 20-34;o Profound MR IQ- 0-19. 