Calculate the mass percentage of $3 \ g$ of solute $A$ dissolved in $18 \ g$ of water. (in $\%$)

Which of the following statements is true?
$(1)$ $200 \ mL$ of $0.2 \ M \ NaOH$ has the same number of moles of solute as $1000 \ mL$ of $1 \ M \ NaOH$.
$(2)$ $200 \ mL$ of $1 \ M \ NaOH$ has the same number of moles as $1000 \ mL$ of $0.2 \ M \ NaOH$.
$(3)$ $100 \ mL$ of $0.2 \ M \ NaOH$ has the same number of moles as $1000 \ mL$ of $1 \ M \ NaOH$.
$(4)$ $2000 \ mL$ of $0.2 \ M \ NaOH$ has the same number of moles as $1000 \ mL$ of $1 \ M \ NaOH$.

If $120 \, g$ of urea (molar mass = $60 \, g/mol$) is dissolved in $1000 \, g$ of water and the density of the resulting solution is $1.15 \, g/mL$,what is the molarity of the solution in $M$?

Which of the following modes of expressing concentration is independent of temperature?

What is the mole fraction of the solute in a $2.5 \, m$ aqueous solution?

To $5.85 \, g$ of $NaCl$,$1 \, kg$ of water is added to prepare a solution. What is the strength of $NaCl$ in this solution? (Molecular weight of $NaCl = 58.5 \, g/mol$)