a bottle has a mass of 70 g when it is epty , 90 g when it is full of water and 96 when it is full of a liquid
what is the density of the liquid
It holds 90=70 = 20 grams of water. That is 20 cm^3 or cc of water.
The liquid has mass of 96 - 70 = 26 grams
so
density = 26 g/20 cc = 1.3 g/cc