Let's denote the amount of sugar to be added as "x" in grams.

Initially, the sugar solution has a total weight of 300 grams, and 40% of it is sugar. This means that the amount of sugar in the solution is:

40% of 300 g = 0.4 x 300 g = 120 g

After adding "x" grams of sugar, the total weight of the solution will be 300 + x grams. The amount of sugar in the solution will also increase to 120 + x grams.

To make a 50% sugar solution, we need to have:

(120 + x) / (300 + x) = 0.5

Solving for "x", we get:

120 + x = 0.5 * (300 + x) 120 + x = 150 + 0.5x 0.5x = 30 x = 60

Therefore, 60 grams of sugar should be added to the solution to make it a 50% sugar solution.