Ratio Problem Solving Finding Numbers In 7:2 Ratio With Sum 81

by ADMIN 63 views

Ratios and proportions are fundamental mathematical concepts that play a crucial role in various real-world applications, ranging from scaling recipes in the kitchen to calculating financial investments. Understanding ratios and proportions is essential for problem-solving in mathematics, science, and everyday life. At its core, a ratio is a comparison of two or more quantities, indicating their relative sizes. It expresses how much of one thing there is compared to another. Ratios can be represented in several ways, including fractions, decimals, and using the colon symbol (:). For instance, a ratio of 3:4 signifies that for every 3 units of one quantity, there are 4 units of another quantity. Proportions, on the other hand, are statements of equality between two ratios. They assert that two ratios are equivalent, meaning that the relationship between the quantities in both ratios is the same. Proportions are often written in the form a/b = c/d, where a, b, c, and d are the terms of the proportion. The concept of proportionality underlies many mathematical and scientific principles, allowing us to make predictions and solve problems involving relationships between quantities.

The power of ratios and proportions lies in their ability to simplify complex comparisons and make calculations easier. When dealing with quantities that are related proportionally, we can use proportions to find unknown values or to scale quantities up or down while maintaining the same relative relationship. This is particularly useful in situations where direct measurement is impractical or impossible. For example, if we know the ratio of ingredients in a recipe and want to make a larger batch, we can use proportions to calculate the required amounts of each ingredient. Similarly, in mapmaking, proportions are used to represent distances on the ground on a smaller scale on the map. By understanding the scale ratio, we can accurately determine actual distances between locations. Moreover, ratios and proportions are essential tools in financial analysis, where they are used to calculate interest rates, investment returns, and profit margins. They are also fundamental in statistics, where they are used to analyze data and draw inferences about populations. In essence, ratios and proportions provide a framework for understanding and quantifying relationships between quantities, enabling us to solve problems and make informed decisions across a wide range of disciplines.

When tackling ratio problems, a systematic approach is crucial for ensuring accuracy and efficiency. Solving ratio problems often involves a series of logical steps that help break down the problem and identify the unknowns. By following a step-by-step method, you can minimize errors and gain a deeper understanding of the underlying concepts. The first step in solving any ratio problem is to carefully read and understand the problem statement. Identify the quantities being compared and the given ratio. Pay close attention to the wording of the problem, as it may provide clues about how the quantities are related. Once you have a clear understanding of the problem, the next step is to set up the ratio equation. This involves expressing the given ratio in a mathematical form, such as a fraction or using the colon symbol. For example, if the ratio of two numbers is 3:5, you can write this as 3/5 or 3:5. If there are unknown quantities in the problem, assign variables to represent them. This will help you to formulate an equation that relates the known and unknown quantities. The third step is to translate the problem into an algebraic equation. This is often the most challenging part of the problem-solving process, as it requires careful interpretation of the problem statement. Look for keywords or phrases that indicate relationships between the quantities, such as “sum,” “difference,” “product,” or “ratio.” Use these clues to construct an equation that accurately represents the problem. For example, if the problem states that the sum of two numbers is 20 and their ratio is 2:3, you can write the equation x + y = 20, where x and y represent the two numbers.

Once you have set up the equation, the next step is to solve for the unknown variables. This may involve using algebraic techniques such as substitution, elimination, or cross-multiplication. Choose the method that is most appropriate for the given equation. After you have found the values of the unknown variables, the final step is to check your answer. Substitute the values back into the original equation or ratio to ensure that they satisfy the given conditions. If your answer does not check out, go back and review your work to identify any errors. In addition to these steps, there are some general strategies that can be helpful when solving ratio problems. One strategy is to simplify the ratio as much as possible before setting up the equation. This can make the calculations easier and reduce the risk of errors. Another strategy is to use a diagram or table to organize the information given in the problem. This can help you to visualize the relationships between the quantities and identify any patterns or connections. Finally, practice is essential for mastering ratio problems. The more you practice, the more comfortable you will become with the problem-solving process and the more confident you will be in your ability to solve these types of problems.

The given problem presents a classic scenario involving ratios and sums, requiring us to find two numbers that adhere to a specific ratio and whose sum equals a particular value. Deconstructing the problem, we can identify the key pieces of information: the ratio of the two numbers is 7:2, and their sum is 81. Our objective is to determine the values of these two numbers. To approach this problem systematically, we can employ the concept of proportional parts. The ratio 7:2 indicates that the two numbers can be represented as 7x and 2x, where x is a common factor. This means that the first number is 7 times the common factor, and the second number is 2 times the same factor. The use of the variable x allows us to express the numbers in terms of a single unknown, simplifying the process of finding their values. By representing the numbers in this way, we can translate the given information into an algebraic equation that can be solved for x.

The next step in solving the problem is to utilize the information about the sum of the numbers. The problem states that the sum of the two numbers is 81. Since we have represented the numbers as 7x and 2x, we can write the equation 7x + 2x = 81. This equation expresses the relationship between the numbers and their sum, allowing us to solve for the common factor x. By combining like terms, we simplify the equation to 9x = 81. This equation is now in a simple form that can be easily solved for x. Dividing both sides of the equation by 9, we find that x = 9. This value of x represents the common factor that relates the two numbers in the ratio. Once we have determined the value of x, we can substitute it back into the expressions for the two numbers, 7x and 2x, to find their actual values. This will give us the specific numbers that satisfy the given ratio and sum conditions. The ability to translate word problems into algebraic equations is a fundamental skill in mathematics, and this problem provides a clear example of how this skill can be applied to solve ratio problems.

With the equation 9x = 81 established, solving the equation becomes a straightforward algebraic process. To isolate x, we divide both sides of the equation by 9, resulting in x = 9. This value of x represents the common factor that determines the magnitude of the two numbers in the ratio. Now that we have found x, we can substitute it back into the expressions for the two numbers, which were represented as 7x and 2x. Substituting x = 9 into 7x, we get 7 * 9 = 63. This means that the first number is 63. Similarly, substituting x = 9 into 2x, we get 2 * 9 = 18. This indicates that the second number is 18. Therefore, the two numbers that satisfy the given conditions are 63 and 18. These numbers are in the ratio 7:2, as 63/18 simplifies to 7/2, and their sum is 63 + 18 = 81, which matches the given sum.

To ensure the accuracy of our solution, we can verify that the numbers 63 and 18 meet both conditions of the problem. First, we check that their ratio is indeed 7:2. Dividing 63 by 18, we get 3.5, which is the same as 7/2. This confirms that the numbers are in the correct ratio. Second, we check that their sum is 81. Adding 63 and 18, we get 81, which matches the given sum. Since the numbers satisfy both conditions, we can confidently conclude that our solution is correct. The process of verifying the solution is an important step in problem-solving, as it helps to catch any errors that may have occurred during the calculation. It also reinforces the understanding of the problem and the solution. This problem demonstrates how algebraic techniques can be used to solve ratio problems, and it highlights the importance of careful substitution and verification in ensuring the accuracy of the solution.

Having determined the two numbers to be 63 and 18, we can now identify the correct answer choice in the problem. Concluding our analysis, the correct answer is B. 63,18. This option lists the numbers in the correct order, with 63 corresponding to the larger part of the ratio (7) and 18 corresponding to the smaller part (2). The problem-solving process we have followed demonstrates a systematic approach to tackling ratio problems, involving the translation of the problem into an algebraic equation, solving for the unknown variable, and verifying the solution. By breaking down the problem into smaller steps, we can minimize errors and gain a deeper understanding of the concepts involved. The key to solving ratio problems lies in understanding the meaning of the ratio and using it to express the quantities in terms of a common factor.

This problem provides a valuable opportunity to reinforce our understanding of ratios and proportions. Ratios are fundamental mathematical tools that allow us to compare quantities and express their relative sizes. Proportions, on the other hand, are statements of equality between two ratios. They are used to solve problems involving scaling, comparison, and relationships between quantities. The ability to work with ratios and proportions is essential in various fields, including mathematics, science, engineering, and finance. By practicing these types of problems, we can develop our problem-solving skills and build a strong foundation for more advanced mathematical concepts. Furthermore, understanding ratios and proportions can help us to make informed decisions in everyday life, such as when comparing prices, calculating discounts, or adjusting recipes. The systematic approach we have used in this problem can be applied to a wide range of ratio problems, making it a valuable tool in our mathematical toolkit.