Question

1 kg of water is mixed with 2 kg of liquid density 3 gram centimetre cube then the average density of mixture will be

Answer 1

density =mass/ volume
water 1gm/cm3
therefore 1kg water nearly 1 lit
density of liquid 3=mass/volume
therefore volume of liquid=2/3lit
total mass of mixture =mass of water + mass of liquid= 1+2=3 kg
total volume = 1+2/3=5/3
density=3/(5/3)=9/5=1.8gm/cm3

Answer 2

mass of water = 1 kg
mass of liquid = 2kg
total mass = 1kg + 2kg = 3kg or 3000g

volume of water = mass of water/density of water = 1000g/1g/cm³ = 1000cm³
volume of liquid = mass of liquid/density of liquid
= 2000g/(3g/cm³)
= 2000/3 cm³

total volume of mixture = 2000/3 + 1000
= 5000/3 cm³


now, density of mixture = total mass/total volume
= (3000g)/(5000/3)
= 9/5 = 1.8 g/cm³