(PLEASE HELP ASAP!!). One's intelligence quotient, or IQ, varies directly as a person's mental age and inversely as that person's chronological age. A person with a mental age of 15 and achronological age of 30 has an IQ of 120: What is the chronological age of a person with a mental age of 20 and an IQ of 120?The chronological age is

Answer:40Step-by-step explanation:This is a variation questionFrom the statement. Let the mental age be M and the chronological  age be C, thenIQ ∝M ∝1/C⇒ IQ ∝ M/CIntroducing the proportionality constant IQ = KM/ CGiven : M = 15, C = 30 , 1Q = 20Substitute the given values into the equation i.e 120 = K x 15/ 30     120 = k/2therefore k = 240substitute k = 240 into the equation, we haveIQ = 240M/CTo find C when IQ is 120 and M is 20, we will substitute into the generated formulai.e 120 = 240 x 20 / c      120c = 480             C = 480/120              C = 40Therefore , the chronological age of a person with mental age of 20 and IQ of 120 is 40