Mathematics

Problem

14. IQ of a person is given by the formula

\mathrm{IQ}=\frac{\mathrm{MA}}{\mathrm{CA}} \times 100,

where MA is mental age and CA is chronological age. If

80 \leq \mathrm{IQ} \leq 140

for a group of 12 years old children, find the range of their mental age.