Exercise 2.3 (Percentage in Real Life)

Exercise 2.3

1. 14 out of the 70 magazines at the bookstore are comedy magazines. What percentage of the magazines at the bookstore are comedy magazines?

Solution:  Total number of magazines in the bookstore = 100 m

Number of comedy magazines = 14

Percentage of commedy magzines = (14 / 70) × 100% = 20%

20% of the magazines are comedy magazines.

2. A tank can hold 50 litres of water. At present, it is only 30 % full. How many litres of water will fill the tank, so that it is 50 % full?

Solution:  Capacity of the tank = 50 litres

Amount of water filled = 30% of 50 litres = 30/100 × 50 = 15 litres

Amount of water to be filled = 50 – 15 = 35 litres

3. Karun bought a pair of shoes at a sale of 25%. If the amount he paid was ₹ 1000, then find the marked price.

Solution:  Let the marked price of the raincoat be ₹ P

Amount he paid at a discount of 25% = ₹ 1000

(Marked Price) – (25% of P) = 1000

P – ( 25/100 × P ) = 1000

P – 1/4 × P = 1000

P (1 – 1/4 ) = 1000

3/4 P = 1000

P = 1000 × 4/3 = 4000 / 3

P = 1333.33

∴ Marked price of the shoes = ₹ 1333

4. An agent of an insurance company gets a commission of 5% on the basic premium he collects. What will be the commission earned by him if he collects ₹ 4800?

Solution:

Premium collected = ₹ 4800

Commission earned = 5% of basic premium

Commission earned for ₹ 4800 = 5% of 4800 = ( 5 / 100 ) × 4800 = ₹ 240

∴ Commission earned = ₹ 240

5. A biology class examined some flowers in a local Grass land. Out of the 40 flowers they saw, 30 were perennials. What percentage of the flowers were perennials?

Solution:

Number of flowers examined = 40

Number of perennials = 30

Percentage = (30/40) × 100% = 75%

75% of the flowers were perennials.

6. Ismail ordered a collection of beads. He received 50 beads in all. Out of that 15 beads were brown. Find the percentage of brown beads?

Solution:

Number of beads received = 50

Number of brown beads = 5

Percentage ol brown beads = (15/50) × 100% = 10%

10% of the beads was brown

7. Ramu scored 20 out of 25 marks in English, 30 out of 40 marks in Science and 68 out of 80 marks in mathematics. In which subject his percentage of marks is best?

Solution:

Ramu's score in English = 20 out of 25

Percentage scored in English = 20/25 × 100% = 80%

Ramu's Score in Science = 30 out of 40

Percentage scored in Science = (30 / 40) × 100% = 75%

Ramu's score in Mathematics = 68 out of 80

Percentage scored in Maths = (68 / 80) × 100% = 85%

85% > 80% > 75% ∴ In Mathematics his percentage of marks is the best.

8. Peter requires 50% to pass. If he gets 280 marks and falls short by 20 marks, what would have been the maximum marks of the exam?

Solution:

Peters score = 280 marks

Marks needed for a pass = 20

∴ Total marks required to get a pass = 280 + 20 = 300

i.e. 50% of total marks = 300

[50/100] × Total marks = 300

1/2 × Total Marks = 300

Total Marks = 300 × 2 = 600

Total marks of the exam = 600

9. Kayal scored 225 marks out of 500 in revision test 1 and 265 out of 500 marks in revision test 2. Find the percentage of increase in her score.

Solution:

Marks scored in revision I = 225

Marks scored in revision II = 265

Change in marks = 265 – 225 = 40

Percentage of increase = [Change in marks / Original marks] × 100 = (40 / 500 ) × 100 = 8%

Percentage of increase in marks = 8%

10. Roja earned ₹ 18,000 per month. She utilized her salary in the ratio 2:1:3 for education, savings and other expenses respectively. Express her usage of income in percentage.

Solution:

Amount of Salary = ₹ 18,000

(i) Total number of parts of salary = 2 + 1 + 3 = 6

Salary is divided into 3 portions as 2/6, 1/6 and 3/6

Portion of salary used for education = 2/6

Salary used for education = 2/6 × 18,000 = ₹ 6,000

Percentage for Education = [6000 / 18000] × 100 = 33.33%

Usage of salary for savings = 1/6 × 18,000 = ₹ 3,000

Percentage for savings = [3000 / 18000] × 100 = 16.67%

Usage of salary for other expenses = 3 / 6 × 18,000 = ₹9,000

Percentage for other expenses = 9000 / 18000 × 100 = 50%

ANSWERS:

Exercise 2.3

1. 20%

2. 10 liters

3. ₹ 1334

4. ₹ 240

5. 75%

6. 30%

7. Mathametics 85 %

8. 600

9. 8%

10. Education − ₹ 6,000 and 33.33%; Savings – ₹ 3,000 and 16.66%; other expenses – ₹ 9,000 and 50%