Shaded Figures Percentage Quiz

Percentages and Their Applications

• Percentages can be interpreted as parts out of 100; for example, 5% means 5 out of every 100.
• Common real-life applications include savings (e.g., Ravi saves 5% of his income), color proportions in wardrobes (e.g., Meera has 20% blue dresses), and commissions from sales (e.g., Rekha earns 10% on books sold).

Converting Percentages to "How Many"

• To determine the actual number from a percentage, multiply the total quantity by the percentage.
• For instance, in a survey of 40 children, if 25% like playing football, then 10 children liked it (25% of 40).

Calculating Increases and Decreases

• To find the percentage of increase or decrease, use the formula:
  Percentage Change = (Amount of Change / Original Amount) x 100.
• Example calculations include a shirt's price decrease from ₹280 to ₹210 and marks increased from 20 to 30.

Pricing in Buying and Selling

• Cost Price (CP) is the price paid for an item, while Selling Price (SP) is the price received upon sale.
• Profit or loss is calculated based on the relationship between CP and SP:
  • Profit when CP < SP: Profit = SP - CP
  • No Profit No Loss when CP = SP
  • Loss when CP > SP: Loss = CP - SP.
• Example: A toy bought for ₹72 and sold for ₹80 incurs a profit of ₹8.

Simple Interest (SI)

• When borrowing money, the principal is the sum borrowed, and interest is the extra amount paid.
• Interest is often expressed as a percentage per annum (e.g., 10% per year).
• The interest for one year can be calculated using the formula:
  Interest = (Principal x Rate x Time) / 100.

Interest Over Multiple Years

• For multiple years, multiply the annual interest by the number of years:
  Total Interest = Annual Interest x Years.
• Example: For ₹100 borrowed at 18% for 3 years, total interest is ₹54 (18% x 3).

Practical Applications of Percentages

• Percentages help compare quantities and understand relationships in everyday decisions, such as investments, price changes, and interest calculations.
• They can also represent ratios and proportions in various contexts (e.g., sales, savings, expenses).

Summary of Key Concepts

• Percentages represent a fraction of 100; conversions between percentages, decimals, and fractions are crucial for calculations.
• Practical applications include interpreting financial statements, assessing price changes, and understanding profit/loss scenarios.
• Knowing how to calculate and interpret percentages is vital for everyday financial decision-making.