Given,
Weight of the solid in air (W1) = 1.5 kgf
Weight of the solid in liquid (W2) = 0.9 kgf
Density of the liquid = 1.2 x 103 kg m-3
R.D. of liquid=1000 kg cm−3Density of liquid in kg m−3=10001.2×103=1.2
R.D. of solid=(W1−W2W1)×R.D. of liquid=(1.5−0.91.5)×1.2=(0.61.5)×1.2=3.0