Question

a solid weighs 80 gram in air and 64 gram in water. calculate the relative density.

Answer 1

Relative density of a object = $\frac{ W_{a} }{ W_{a} - W_{u} }$
=80/(80-64)
=80/16
=5

Answer 2

RD = Wt of air of object / Wt of the air - wt of the water 

ans = 5