Percentage Aptitude

Percentage is a fundamental mathematical concept used to express a number as a fraction of 100. It is widely used in various fields, including finance, statistics, and everyday calculations. Understanding percentages is crucial for interpreting data, comparing proportions, and solving problems related to increases or decreases in quantities.

1. What is 20% of 150?

20% of 150 = (20/100) * 150 = 30.

2. If 40% of a number is 80, what is 60% of that number?

Let the number be x.
40% of x = 80 ⇒ (40/100) * x = 80 ⇒ x = 80 * (100/40) = 200.
60% of x = (60/100) * 200 = 120.

3. A student scored 75% marks in an exam. If the total marks were 800, how many marks did the student score?

75% of 800 = (75/100) * 800 = 600.

4. The price of a shirt was increased by 25%. If the new price is $125, what was the original price?

Let the original price be x.
New price = x + 25% of x = x + (25/100) * x = 125.
1.25x = 125 ⇒ x = 125 / 1.25 = $100.

5. A population of a town increases annually by 10%. If the current population is 110000, what was it last year?

Let the population last year be x.
Current population = x + 10% of x = x + (10/100) * x = 110000.
1.10x = 110000 ⇒ x = 110000 / 1.10 = 100000.

6. If 30% of a number is 45, what is 50% of that number?

Let the number be x.
30% of x = 45 ⇒ (30/100) * x = 45 ⇒ x = 45 * (100/30) = 150.
50% of x = (50/100) * 150 = 75.

7. A student needs to score 40% marks to pass an exam. If the total marks are 700, how many marks does the student need to pass?

Marks needed to pass = 40% of 700 = (40/100) * 700 = 280.

8. The price of a commodity decreases by 20%. If the new price is $160, what was the original price?

Let the original price be x.
New price = x - 20% of x = x - (20/100) * x = 160.
0.80x = 160 ⇒ x = 160 / 0.80 = $200.

9. In an election, a candidate who gets 70% of the votes is elected by a majority of 300 votes. What is the total number of votes?

Let the total number of votes be x.
Votes received by the candidate = 70% of x = (70/100) * x.
Votes received by the other candidate = x - (70/100) * x.
The majority of votes = (70/100) * x - (x - (70/100) * x) = 300.
0.70x - x + 0.70x = 300.
0.40x = 300 ⇒ x = 300 / 0.40 = 1000.

10. A person's salary is increased by 15%. If the new salary is $5750, what was the original salary?

Let the original salary be x.
New salary = x + 15% of x = x + (15/100) * x = 5750.
1.15x = 5750 ⇒ x = 5750 / 1.15 = $5000.

11. What percent of 250 is 75?

Percentage = (75 / 250) * 100 = 30%.

12. The price of a jacket is increased by 25%. If the new price is $250, what was the original price?

Let the original price be x.
New price = x + 25% of x = 1.25x = $250.
x = 250 / 1.25 = $200.

13. In a school, 60% of the students are boys. If there are 240 boys, what is the total number of students in the school?

Let the total number of students be x.
60% of x = 240 ⇒ (60/100) * x = 240 ⇒ x = 240 * (100/60) = 400.

14. A person spends 30% of his salary on rent and 40% on food. If he spends $420 on rent, what is his total salary?

Rent = 30% of salary = $420.
Total salary = 420 / (30/100) = $1400.

15. If the population of a town increases by 10% in a year, and the present population is 33000, what was it a year ago?

Let the population a year ago be x.
Current population = x + 10% of x = 1.10x = 33000.
x = 33000 / 1.10 = 30000.

16. What is 45% of 400?

45% of 400 = (45/100) * 400 = 180.

17. A student scored 180 marks out of 240 in an exam. What percentage did the student score?

Percentage score = (180 / 240) * 100 = 75%.

18. If 25% of a number is 50, what is 40% of that number?

Let the number be x.
25% of x = 50 ⇒ (25/100) * x = 50 ⇒ x = 50 * (100/25) = 200.
40% of x = (40/100) * 200 = 80.

19. The price of a product is decreased by 20%. If the new price is $120, what was the original price?

Let the original price be x.
New price = x - 20% of x = 0.80x = $120.
x = 120 / 0.80 = $150.

20. A fruit seller had 300 apples. He sold 20% of them on the first day. How many apples did he sell?

20% of 300 apples = (20/100) * 300 = 60 apples.