Ratios Introduction — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. A pancake recipe uses 3 cups flour to 2 cups milk; for 6 cups flour, you need 4 cups milk.
Doubling both parts keeps 3:2 equivalent to 6:4, so 6 cups flour needs 4 cups milk.
2. Paint mixes 1 part blue to 4 parts white; for 5 parts blue, you need 20 parts white.
Scaling 1:4 by 5 gives 5:20, so 5 parts blue needs 20 parts white.
3. Simplify the ratio 9:12 to lowest terms: 3:4.
9 and 12 share factor 3; dividing gives 3:4, the simplest form.
4. A juice recipe uses 2 cups orange to 5 cups water; tripled, it needs 15 cups water.
Tripling 2:5 gives 6:15, so the recipe needs 15 cups of water.
5. If 14:21 is a ratio, simplifying gives 2:3.
14 and 21 share factor 7; dividing both by 7 gives 2:3.
6. A bread recipe uses 4 cups flour to 1 cup water; for 12 cups flour, you need 3 cups water.
Scaling 4:1 by 3 gives 12:3, so 12 cups flour needs 3 cups water.
7. An equivalent ratio of 6:9 in lowest terms is 2:3.
6 and 9 share factor 3; dividing gives 2:3, the simplest form.
8. Color mix uses 5 drops red to 2 drops yellow; doubled, it uses 10 drops red.
Doubling 5:2 gives 10:4, so 10 drops of red are needed.
9. Simplify the ratio 20:25 to lowest terms: 4:5.
20 and 25 share factor 5; dividing gives 4:5, the simplest form.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Recipe 2:3 doubled
→ 4:6
4:6
Mix 6:9 simplified
→ 2:3
2:3
Ratio 1:5 tripled
→ 3:15
3:15
Ratio 8:12 simplified
→ 2:3 simplified from 8:12
2:3 simplified from 8:12
Each pair shows the same ratio in a different equivalent form by scaling or simplifying.