How much water should be added to $200 \, cc$ of a semi-normal solution of $NaOH$ to make it exactly deci-normal?

What is meant by mass percentage $( \% w/w )$?

$A$ commercially sold concentrated $HCl$ is $35 \%$ $HCl$ by mass. If the density of this commercial acid is $1.46 \ g/mL$,the molarity of this solution is $....M$.
(Atomic mass : $Cl = 35.5 \ amu, H = 1 \ amu$)

The strength of a solution $(S)$ in $g/L$ is related to its normality $(N)$ and equivalent weight $(E)$ of the solute by the formula:

For a solution containing $0.03659 \ g/mL$ of $HCl$ and a solution containing $0.04509 \ g/mL$ of acetic acid $(CH_3COOH)$,which of the following is true?

If $98 \, mg$ of $H_2SO_4$ is present in $100 \, g$ of solution,what is the molarity of the solution? (Given: density of solution = $1.25 \, g/mL$)