A 25.0 cm³ aliquot of a solution containing Fe²⁺ and Fe³⁺ ions was acidified and titrated against 0.0200 mol dm⁻³ potassium manganate(VII) solution, requiring 15.0 cm³. The solution was then reduced by zinc and after filtering off the excess zinc, was titrated with the same potassium manganate(VII) solution, requiring 19.0 cm³. Calculate the concentrations of the Fe²⁺ and Fe³⁺ in the solution.