Percentage of students not interested = (100 - 72)% = 28%.\nNumber of students not interested = 28% of 25 = (28 / 100) × 25 = 7.

Discount = Marked Price - Sale Price = 840 - 714 = ₹126.\nDiscount % = (Discount / Marked Price) × 100 = (126 / 840) × 100 = 15%.

Profit = Selling Price - Cost Price = 600 - 500 = ₹100.\nProfit % = (Profit / Cost Price) × 100 = (100 / 500) × 100 = 20%.

Question 1

Find the ratio of 50 paise to ₹5.

Accepted Answer

To find the ratio, convert both quantities to the same unit: ₹5 = 500 paise.
Ratio = 50 paise : 500 paise = 1 : 10.

Question 2

Convert the ratio 3 : 4 into percentage.

Accepted Answer

To convert a ratio into percentage, multiply by 100: (3 / 4) × 100% = 75%.

Question 3

If 72% of 25 students are interested in mathematics, how many are NOT interested in mathematics?

Accepted Answer

Percentage of students not interested = (100 - 72)% = 28%.
Number of students not interested = 28% of 25 = (28 / 100) × 25 = 7.

Question 4

An item marked at ₹840 is sold for ₹714. What is the discount percentage?

Accepted Answer

Discount = Marked Price - Sale Price = 840 - 714 = ₹126.
Discount % = (Discount / Marked Price) × 100 = (126 / 840) × 100 = 15%.

Question 5

The cost price of an article is ₹500 and it is sold for ₹600. Find the profit percentage.

Accepted Answer

Profit = Selling Price - Cost Price = 600 - 500 = ₹100.
Profit % = (Profit / Cost Price) × 100 = (100 / 500) × 100 = 20%.

Comparing Quantities — CBSE Class 8 Mathematics Important Questions & Revision Notes