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%.

Let the original price be ₹x.\nx + (10% of x) = 3300 ⇒ 1.10 x = 3300 ⇒ x = 3300 / 1.10 = ₹3,000.

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

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 3

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 4

Find the compound interest on ₹10,000 for 2 years at 10% per annum compounded annually.

Accepted Answer

A = P(1 + R/100)^n = 10000 × (1 + 10/100)^2 = 10000 × (11/10)^2 = ₹12,100.
Compound Interest (CI) = A - P = 12,100 - 10,000 = ₹2,100.

Question 5

Waheeda bought an air cooler for ₹3,300 including a tax of 10%. Find the price of the air cooler before tax was added.

Accepted Answer

Let the original price be ₹x.
x + (10% of x) = 3300 ⇒ 1.10 x = 3300 ⇒ x = 3300 / 1.10 = ₹3,000.

Comparing Quantities