90. Solving a chemistry problem

8. A mixture of isopropanol and n-propanol was separated by gas-liquid chromatography in a column 1 m long, peaks were obtained on the chromatogram (l is the distance from the sample injection to the maximum of the peak of this component, mm, h and μ is the height and width of the peak, respectively, in mm) :
isopropanol l = 17.5 h = 52.5 μ = 5.0
n-propanol l = 32.5 h = 40.0 μ = 7.5
Calculate the number of theoretical plates, the height equivalent to the theoretical plate, and the mass fraction of each alcohol in the mixture.