A solution of sugar is obtained by mixing 200g of its 25% solution and 500g of its 40% solution (both by mass). The mass percentage of the resulting sugar solution is ______ (Nearest integer)

Mass of sugar present in 200g of solution = (200) (0.25) = 50g
Mass of sugar present in 500g of solution = (500) (0.4) = 200g
Mass percentage of sugar in the final mixture 
$\begin{array}{l}=\frac{(50+200)}{200+500}\times 100\\ =35.71\\ =36\left(\text{ nearest integer}\right)\end{array}$