Serena added 10 grams of sugar into 20 grams of water. She made ___ grams of ___% sugar syrup

Answer: She (Serena) made 30 grams of 33.33% sugar syrup. Solution: 10 grams sugar + 20 grams water As 10 grams of sugar added to 20 grams of water, total mixture became 30 grams. Percentage of sugar in total mixture (sugar syrup) = 10 grams sugar in 30 grams syrup. % by mass = [ (mass of solute) / (mass of solute + mass of solvent) ] * 100 This gives = [ (10) / (10+20) ] * 100 = 33.33%

She made 30 grams of 50% sugar syrup.

10 grams is 50% of 20 grams. Its 30 grams of syrup but ratio water:sugar is 2:1 so it's 50% syrup.