Let's call the amount of sugar needed to make 200 grams of 15% sugar syrup "s".
From the information given, we know that 15% of the syrup is sugar, so 200 grams * 15% = 200 grams * 0.15 = 30 grams of the syrup is sugar.
Therefore, the amount of sugar needed is equal to 30 grams, or s = 30 grams.