High school math. Direct frequency.
Because the interval [10, 12] does not contain 12, it should be the frequency of data falling outside [10, 12] = (0.02+0.05+0./kloc-) Frequency of data falling outside [10, 12] =1-0.82 = 0.18; The frequency of samples falling within [10, 12] is 200×0. 18=36.