Answer: b) 1-n= 1/(1+e)
• e is the void ratio.
• n is the porosity.
Void ratio is simply the ratio of volume of void to the volume of soil solid.
i.e. , e = Vv / Vs
e = Vv / Vs = n/(1+n) n= Vv/V = e/(1+e) n= e x (1-n)
∴ 1-n = 1/(1+e)
Hence, option (b) is the correct relationship between porosity and void ratio.