Calculate the percentage composition of a solution obtained by mixing 200 g of a `20%` and 300 g of a `30%` solution by weight.

Calculate the percentage composition of a solution obtained by mixing 200 g of a 30% and 300 g of a 20% solution by weight.

Calculate the percentage composition in terms of mass of solution obtained by mixing 300 g of a 25% and 400 g of a 40% solution by mass.

Calculate the percentage composition in terms of mass of solution obtained by mixing 300 g of a 25% and 400 g of a 40% solution by mass.

Calculate the percentage composition in terms of mass of solution obtained by mixing 300 g of a 25 % and 400 g of a 40 % solution by mass.

Calculate the mass precent of a solution obtine by mixing 100 g of 10% urea solution with 150 g of 15% urea solution.

Calculate the concentration of a solution obtained by mixing 300 g of 25% by weight solution of NH_(4)Cl and 150 g of 40% by weight solution of NH_(4)Cl .