Find the maximum load P (in kN) if the overall deformation may not exceed 3 mm: a steel segment (L = 1000 mm, A = 500 mm^{2}, E = 200 GPa) and an aluminium segment (L = 1500 mm, A = 300 mm^{2}, E = 70 GPa) are joined end to end; P acts at the free end of the steel (toward the bar), 3P at the junction (away from the aluminium side) and 2P at the free end of the aluminium (outward).