Your ratio is 4:1 because it takes 4 cups of water for every cup of sugar.
Let's first find how many students bring their lunch to school. This is 30% of 300. To find this value, convert the percentage to a fraction (or decimal) and multiply:

Since 90 students bring their lunch to school, we can say 210 students do not bring their lunch to school. (300 - 90 = 210)
Answer:
jil got 18 chocolates
Step-by-step explanation:
let the ratio constants be x,
so, jil has 3x chocolates
katie has 4x chocolates
and we know total chocolates = 42
then,
=》3x + 4x = 42
=》7x = 42
=》x = 42 ÷ 7
=》x = 6
so, jil got 3x = (3 × 6) = 18 chocolates
katie got 4x = (4 × 6) = 24 chocolates