When water and methanol, CH₃OH(l), are mixed, the total volume of the resulting solution is not equal to the sum of the pure liquid volumes. When 72.061 g H₂O and 192.25 g CH₃OH are mixed at 25 °C, the resulting solution has a density of 0.86070 g/mL. At 25 °C, the densities of water and methanol are 0.99705 g/mL and 0.78706 g/mL, respectively.

(a) Calculate the volumes of the pure liquid samples and the solution, and show that the pure liquid volumes are not additive.

(b) Calculate the molarity of CH₃OH in this solution.