An object weighs 0.250 kgf in air, 0.150 kgf in water and 0.125 kgf in an oil. Find out the density of the object and the oil.

Upthrust = Weight - Apparent weight

= 0.250 kgf - 0. 150 kgf

= 0.100 kgf

Density = mass / volume

volume = mass / density

= 0.100 kg / (1000 kg / m³)

= 0.0001 m³

density of object  = mass / volume

= 0.250 kg / 0.0001 m³

= 2500 kg / m³

upthrust of oil = Weight - Apparent weight

= 0.250 kgf - 0.125 kgf

= 0.125 kgf

density = mass / volume

= 0.125 kg / 0.0001 m³

= 1250 kg/m³

density of the object = 2500 kg / m³

density of oil = 1250 kg / m³

because if the tool that you are using is not balanced it there would be false mass.