What type of solution is gasoline?

The amount of water that should be added to $500 \, mL$ of $0.5 \, N$ solution of $NaOH$ to give a concentration of $10 \, mg$ per $mL$ is (in $, mL$)

The number of moles of a solute in its solution is $20$ and the total number of moles is $80$. The mole fraction of the solute is:

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

$A$ $6.50$ molal solution of $KOH$ $(aq.)$ has a density of $1.89 \ g \ cm^{-3}$. The molarity of the solution is .......... $mol \ dm^{-3}$.
(Round off to the Nearest Integer).
[Atomic masses: $K = 39.0 \ u, O = 16.0 \ u, H = 1.0 \ u$]

$A$ molar solution is one that contains one mole of a solute in