Question

a solid bottle weighs 20g when filled with water when it is filled with oil 21.76g what is the density of oil? pls say the ans with formal

Answer 1

You can use cross multiplication formula

The density of water = 1g/cm³

If 20g in that bottle will give 1g/cm³
Then 21.76g = 1g/cm³ × 21.76g/20g
                    = 1.088g/cm³

Or 

find the volume of the bottle

density of water = 1g/cm³
volume = density × mass
             = 1g/cm³ × 20g
             =  20 cm3

Find density of the oil using the its volume in the bottle and its mass
 
Density = mass/volume
             
            =   21.76g ÷ 20cm³
  
         = 1.088g/cm³