$80$ kg of Na$2$SO$4($molecular weight $=142)$ is present in $330$ kg of an aqueous solution. The solution is cooled such that. $80$ kg of Na$2$SO$4\mathrm{.}10$H$2$O crystals separate out. The weight fraction of Na$2$SO$4$ in the remaining solution is

$0$

$0\mathrm{.}18$

$0\mathrm{.}24$

$1$