ANS:C - 64%

As I know, Question num 216 is incorrect, the given water density is 1.84 but this is bulk density 1.84 so that.

Yd=yt/1+w.
So w=.15.

Se=wg.
So s =.64. 216 = if dry density, water density and specific gravity of solids of a given soil sample are 1.6 g/cc , 1.84 g/cc and 2.56 respectively, the porosity of the soil sample is? 66% will be the Answer.

Dry density=1.6.
water density=1.84.
e=?.

n = e/1+e=0.66 or 66%.