CBSE Math Chapter: Comparing Quantities

Percentage Calculations

• To find what percentage of 120 is 24, use the formula: (Part/Whole) × 100. Therefore, (24/120) × 100 = 20%. So, 24 is 20% of 120.

Discount and Cost Price

• A fruit vendor offers a 15% discount on all fruits.
• For a fruit with a marked price of ₹120, the selling price after discount is calculated as: Selling Price = Marked Price - (Discount × Marked Price) = ₹120 - (0.15 × ₹120) = ₹102.
• To find the cost price (CP), if needed, we need additional information about profit margins or other costs.

Exam Performance Percentage

• A student scored 420 out of a total of 600 marks.
• The percentage of marks is calculated as: (Obtained Marks/Total Marks) × 100 = (420/600) × 100 = 70%.
• Thus, the student obtained 70% marks in the examination.

Profit Calculation

• A shopkeeper marks his goods 25% above the cost price (CP).
• If CP is denoted as CP, then the marked price (MP) becomes: MP = CP + (0.25 × CP) = 1.25 × CP.
• The shopkeeper sells the goods at a 10% discount: Selling Price (SP) = MP - (10% of MP) = MP - (0.10 × MP) = 0.90 × MP.
• Profit percentage can be derived from the selling price and cost price using: Profit Percentage = [(SP - CP)/CP] × 100.

Value of x from Percentage

• If 15% of x is equal to 24, the equation can be expressed as: 0.15 × x = 24.
• To find x, rearrange the equation: x = 24 / 0.15 = 160. Thus, the value of x is 160.