How much sugar do you need to add to 300g 30% sugar syrup to get 40% syrup?

Find the amount of sugar contained in the original amount of sugar syrup (multiply the amount of syrup by the number of percent and divide by 100):

300 * 30/100 = 90 g.

Let’s take the amount of added sugar as x, then:

90 + x – new amount of sugar;

300 + x is the new amount of sugar syrup.

We get the equation:

(90 + x) / (300 + x) = 40/100;

90 + x = 120 + 0.4x;

x = 50.