Calculations and Percentages - Exercise 12.2

Calculations and Percentages

• Finding percentages: To find a percentage of a value, multiply the value by the percentage divided by 100
• Example: 35% of ₹1000 is ₹350 (1000 x 35 / 100)
• Finding the remaining balance: Subtract the calculated percentage from the original value
• Example: Remaining balance after ₹350 spent from ₹1000 is ₹650 (1000 - 350)

Exercise 12.2 - Finding Percentage

• Percentage of money: Calculating the percentage of a given amount of money.
• Example: 20% of ₹80 is ₹16 (80 x 20 / 100)

Exercise 12.2 - Finding values

• Percentage of lengths: Calculating a percentage of a given length.
• Example: 25% of 440m is 110m (440 x 25 / 100)

Exercise 12.2 - Finding Ratios

• Finding percentage of items: Calculating the percentage of items in a given collection
• Example: 10% of 840 books is 84 books (840 x 10/100)

Exercise 12.2 - Finding Time Ratios

• Finding time ratios: Calculating the percentage of time as shown in minutes or hours
• Example: 10 minutes is 16.67% of 1 hour (10 minutes/60 minutes * 100)

Exercise 12.2 - Finding Discounts and Total Costs

• Discounts: Calculating discounts on items based on percentage of the total cost.

Finding Losses and Gains

• Loss calculation: Determines the amount of loss based on calculations
• Example: If the cost price is ₹160 and the selling price is ₹150, then the loss is ₹10 (160-150)

Exercise- Different Calculations and Problems

• Problem Example 1: Rahul bought an item for ₹1000 and sold it for ₹900. Calculate the loss percentage.
• Problem Example 2: Ganesh purchased a bicycle for ₹150 and sold it for ₹160. Determine the profit percentage.

Additional Problems

• Problem Example 3: A crate of 90 bottles had 18 broken bottles. What percentage of the bottles were intact?
• Problem Example 4: A school has 2800 students where 1000 are boys. Calculate the percentage of girls.
• Problem Example 5: If 45% of a village are women and the number of men is 1100, find the total population of the village.