Freshly prepared aluminium and magnesium hydroxides are stirred vigorously in a buffer solution containing `0.25M` of ammonium chloride and `0.05M` of ammonium hydroxide. Calculate the concentration of aluminium and magesium ions in solution `(K_(b) NH_(4)OH = 1.8 xx 10^(-5), K_(sp) Mg(OH)_(2) = 6 xx 10^(-10), K_(sp) A1(OH)_(3) = 6 xx 10^(-32)`.