Which of the following factors affect the molarity of a solution?

$A$ solution of sugar is obtained by mixing $200 \ g$ of its $25 \%$ solution and $500 \ g$ of its $40 \%$ solution (both by mass). The mass percentage of the resulting sugar solution is $..........$. (Nearest integer)

$0.1 \ mol$ of $NaCl$ is dissolved in $100 \ g$ of water. The mole fraction of $NaCl$ is

The density of $3 \ m$ solution of $NaOH$ is $1.110 \ g \ mL^{-1}$. Calculate the molarity of the solution. (in $M$)

Which of the following is incorrect for the mole fraction $(x)$?

What is the mole fraction of the solute in a $1 \, m$ (molal) aqueous solution?