In a certain school, 20% of students are below 8 years of age. the number of students above 8 years of age is of the number of students of 8 years of age which is 48. what is the total number of students in the school?

In a certain school, 20% of students are below 8 years of age. The number of students above 8 years of age is 2/3 of the number of students of 8 years of age which is 48. What is the total number of students in the school?

Given:

• Number of students above 8 years = (number of students with 8 years) × 2/3 = 48
• So, the number of students with 8 years = 48 × 3/2 = 72
• Also, the total number of students = (number of students below 8 years) + (number of students with 8 years) + (number of students above 8 years)

Now, let's calculate:

• Number of students below 8 years = 20% of total students = (20/100) × x = x/5
• Total number of students = x
• Number of students above 8 years = 48

So, the equation becomes: x = (x/5) + 48 + 72

Solving for x: x = (x/5) + 120 5x = x + 600 4x = 600 x = 600 / 4 = 150

Therefore, there are 150 students in the school.

Applications of Percentages in Real World

Percentages are extensively used in various real-world applications across different fields. Here are some examples:

1. Finance and Economics:

   • Interest Rates: Percentages are used to calculate interest rates on loans, mortgages, and investments. For example, mortgage rates, annual percentage rates (APR), and compound interest.
   • Stock Market: Percentages are used to indicate changes in stock prices, market gains or losses, and to calculate returns on investments.
   • Inflation and Deflation: Economists use percentages to measure changes in the price level of goods and services over time, which helps in understanding inflation and deflation rates.

2. Business and Marketing:

   • Discounts and Sales: Percentages are used to calculate discounts, markdowns, and sales prices. Businesses often offer discounts as a percentage off the original price to attract customers.
   • Profit Margin: Percentages help businesses determine their profit margins by calculating the percentage difference between the cost price and the selling price of goods or services.
   • Market Share: Percentages are used to analyze market share, which indicates the portion of total sales within a specific industry that a company controls.

3. Healthcare:

   • Medical Tests: Percentages are used to interpret medical test results, such as the accuracy and reliability of diagnostic tests, sensitivity, and specificity.
   • Health Statistics: Percentages are used to represent statistics related to disease prevalence, mortality rates, vaccination coverage, and other public health indicators.

4. Education:

   • Grading Systems: Percentages are commonly used in grading systems to evaluate student performance on assignments, tests, and exams.
   • School Funding: Percentages are used in budgeting and allocating funds to schools based on criteria like student enrollment, attendance rates, and academic performance.

5. Sports and Athletics:

   • Player Statistics: Percentages are used to calculate various statistics in sports, such as batting averages in baseball, shooting percentages in basketball, and completion rates in football.
   • Winning Percentages: Teams' winning percentages are calculated based on the number of games won versus the total number of games played.

6. Science and Engineering:

   • Chemistry: Percentages are used in chemical reactions to express the composition of compounds, reaction yields, and concentrations of solutions.
   • Physics and Engineering: Percentages are used in calculations related to mechanical advantage, efficiency, error margins, and other quantitative analyses.

These are just a few examples, but percentages are pervasive in almost every aspect of daily life and are crucial for making informed decisions and understanding quantitative information.