Hello there! Ratios are super fun, and I'm happy to help you get ready for your exam. Let's make sure you ace it!
Quick Study Guide
- What is a Ratio? A ratio compares two or more quantities of the same kind. It tells us how much of one thing there is compared to another. For example, if you have 3 red balls and 2 blue balls, the ratio of red to blue is $3$ to $2$.
- Ways to Write a Ratio: You can write ratios in three main ways:
- Using a colon: $A : B$ (e.g., $3 : 2$)
- Using the word "to": $A$ to $B$ (e.g., $3$ to $2$)
- As a fraction: $\frac{A}{B}$ (e.g., $\frac{3}{2}$)
Always make sure the order of the numbers matches the order of the items you are comparing!
- Simplifying Ratios: Just like fractions, ratios can often be simplified to their simplest form. To do this, divide both parts of the ratio by their greatest common factor (GCF). For example, the ratio $10 : 5$ can be simplified by dividing both numbers by $5$, which gives you $2 : 1$.
- Parts of a Ratio:
- Part-to-Part Ratio: Compares one part of a group to another part. (e.g., apples to bananas).
- Part-to-Whole Ratio: Compares one part of a group to the total number in the group. (e.g., apples to total fruit).
Practice Quiz
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Question 1: In a garden, there are 7 rose bushes and 4 sunflower plants. What is the ratio of rose bushes to sunflower plants?
- $4 : 7$
- $7 : 4$
- $7 : 11$
- $4 : 11$
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Question 2: A recipe calls for 3 cups of water for every 1 cup of rice. How would you write the ratio of water to rice using a fraction?
- $\frac{1}{3}$
- $\frac{3}{1}$
- $3$ to $1$
- $1 : 3$
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Question 3: Simplify the ratio $15 : 20$.
- $5 : 4$
- $3 : 5$
- $4 : 3$
- $3 : 4$
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Question 4: There are 6 yellow pencils and 18 blue pencils in a box. What is the ratio of yellow pencils to blue pencils in its simplest form?
- $6 : 18$
- $18 : 6$
- $1 : 3$
- $3 : 1$
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Question 5: A class has 12 boys and 18 girls. What is the ratio of boys to the total number of students?
- $12 : 18$
- $18 : 12$
- $12 : 30$
- $30 : 12$
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Question 6: If the ratio of cats to dogs at a pet store is $2 : 5$, and there are 10 cats, how many dogs are there?
- $15$ dogs
- $20$ dogs
- $25$ dogs
- $50$ dogs
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Question 7: Which of the following ratios is equivalent to $10 : 15$?
- $2 : 3$
- $3 : 2$
- $5 : 10$
- $20 : 25$
Click to see Answers
1. B ($7 : 4$)
2. B ($\frac{3}{1}$)
3. D ($3 : 4$)
4. C ($1 : 3$)
5. C ($12 : 30$)
6. C ($25$ dogs)
7. A ($2 : 3$)