A piece of metal weighs 46 g in air and 30 g in liquid of density `1.24 xx 10^3 kg m^(-3)` kept at `27^0C`. When the temperature of the liquid is raised to `42^0C`, the metal piece weights 30.5 g . The density of the liquid at `42^0 C` is `1.20 xx 10^3 kg m^(-3)`. Calculate the coefficient of linear expansion of the metal.