Question

a body weights 200gm in air 180gm in a liquid and 175 gm in water. the density of the liquid is

Answer 1

density of water is 1
if loss in weight is 25 density is 1
if loss in weight is 1 density is 1/25
if loss in weight is 20 density is 1/25*20
= 0.8

Answer 2

the body weighs 200gm in air then,
200= mg. (m= mass= volume of body times the density of body)
and it weighs 175 gm in water ( density of water= 1gm per cubic cm)
then,
175= 200-(V×1×g) ..........(1). (V= volume of body , g= acceleration due to gravity)
from (1) we get ,
V= 2.5 cc.
in unknown liquid (suppose its density be d )it weighs 180 then,
180= 200- (2.5×d×g)........(2)
from (2) we get density d = 0.8 g per cc