Answer
11.89%
Work Step by Step
Here we need to calculate the mass percent of sugar.
Mass % is given by $=$ (Mass of Solute)$\times$ 100/ (Mass of Solution)
Here, the mass of solute (sugar)= 42g
Mass of solvent (water)= 311g
Mass of solution (solute + solvent) = 353g
Therefore Mass Percent of sugar $=$ $\frac{42 \times 100}{353}$
$=$ 11.89%