`M_(1) =` mass of the metal piece in air
`M_(2) =` mass of the metal piece in liquid at `30^(@)C`
`M_(3) =` Mass of the metal piece in liequid at `40^(@)C`
`rho_(1) =` density of liquid at `30^(@)C`
`rho_(2) =` density of liquid at `40^(@)C`
Mass expelled `Deltam_(1) = M_(1) - M_(2) = V_(1)rho_(1)` at `30^(@)C`
`Deltam_(2) = M_(1) - M_(3) = V_(2)rho_(2)` at `40^(0)C, (20)/(18) = (V_(1)rho_(1))/(V_(2)rho_(2))`
`(10)/(9) = (V_(1) xx 1.5 xx 10^(3))/(V_(1)(1 + gammaDeltat) xx 1.25 xx 10^(3)), 1 + gammaDeltat = (9 xx 1.2)/(10)`
`= (10.8)/(10) = 1.08, gammaDeltat = 1.08 - 1, 3alpha = 0.08`
`alpha = (0.08)/(3) = :. alpha = 2.6 xx 10^(-3//@)C`
