Which method is used to remove salt from sea water?

The osmotic pressure in atmospheres of a $10\%$ solution of cane sugar at $69\,^oC$ is:

What is the osmotic pressure (in $atm$) of $0.02 \ M$ aqueous glucose solution at $300 \ K$?
$(R=0.082 \ L \ atm \ mol^{-1} \ K^{-1})$

When $10 \ g$ of glucose (osmotic pressure $P_1$),$10 \ g$ of urea (osmotic pressure $P_2$),and $10 \ g$ of sucrose (osmotic pressure $P_3$) are dissolved in $250 \ mL$ of water,the correct relationship between the osmotic pressures of these solutions is:

The osmotic pressure of a solution containing $3 \ g$ of glucose (molar mass = $180 \ g/mol$) in $60 \ g$ of water at $15^\circ C$ (density = $1 \ g/mL$) is ....... $atm$.

Calculate the osmotic pressure of $0.03 \ mol$ of non-electrolyte solute dissolved in $0.1 \ dm^3$ of water at $300 \ K \ [R=0.0821 \ dm^3 \ atm \ mol^{-1} \ K^{-1}]$ (in $atm$)