A particle is simultaneously subjected to three simple harmonic motions, all of the same frequency and in the x direction. If the amplitudes are 0.25, 0.20, and 0.15 mm, respectively, and the phase difference between the first and second is 45°, and between the second and third is 30°, find the amplitude of the resultant displacement and its phase relative to the first (0.25-mm amplitude) component.