Finding a fraction of a ratio involves expressing one part of the ratio as a fraction of the whole. Here's how you do it:
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Understand the Ratio: A ratio compares two or more quantities. For example, a ratio of 2:3 compares two quantities where one is 2 parts and the other is 3 parts.
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Calculate the Total: Add the individual parts of the ratio to find the total number of parts. In the example above (2:3), the total is 2 + 3 = 5 parts.
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Express as a Fraction: To find the fraction representing one part of the ratio, place the value of that part over the total number of parts.
- The first part of the ratio (2) can be expressed as the fraction 2/5.
- The second part of the ratio (3) can be expressed as the fraction 3/5.
Example:
Let's say a cake recipe calls for flour and sugar in a ratio of 4:1. What fraction of the recipe is flour?
- Ratio: Flour : Sugar = 4:1
- Total Parts: 4 + 1 = 5
- Fraction of Flour: 4/5
Therefore, flour makes up 4/5 of the recipe.
General Formula:
If the ratio is a:b, then:
- The fraction representing a is a / (a + b).
- The fraction representing b is b / (a + b).
Key Points:
- Ratios represent proportions.
- Expressing parts of a ratio as fractions allows you to easily understand the proportion each part contributes to the whole.
- Simplifying the resulting fraction is often helpful for clearer understanding. For example, if you get the fraction 4/6, simplify it to 2/3.