Percentage Problems

Practice aptitude questions on percentages

Question 1:

Two students appeared at an examination. One secured 9 marks more than the other, and his marks were 56% of the total. What are their marks?

Explanation:

Let their marks be **(x + 9)** and **x**.

Since:
(x + 9) = (56/100) × (x + 9 + x)

Multiplying both sides by **100**:
25(x + 9) = 14(2x + 9)

Expanding:
25x + 225 = 28x + 126
3x = 99
x = 33

So, their marks are **42 and 33**.
Final Answer: 42, 33.

Question 2:

If the price of a product is increased by 25%, by what percent should the consumption be reduced to maintain the same expense?

Explanation:

If the price increases by **R%**, the reduction required in consumption is:

(R / (100 + R)) × 100

Substituting **R = 25**:
(25 / 125) × 100 = 20%

Final Answer: 20%.

Question 3:

If 45% of a number is 315, what is the number?

Explanation:

Let the number be **X**.

45% of X = 315

Solving for X:
X = (315 × 100) / 45
X = 700

Final Answer: 700.

Question 4:

What percentage of 200 is 80?

Explanation:

Using the percentage formula:
(80 / 200) × 100

= 40%

Final Answer: 40%.