weight/weight percentage is the percentage of mass of solute from the mass of the whole solution
w/w % = 32.7 %
this means that in a solution of 100 g - mass of KCl is 32.7 g
since solution is made of water and KCl
then the mass of water is - 100 - 32.7 = 67.3 g
therefore in 100 g of solution - 67.3 g of the solution is water