Fractions in Disguise is Class 8 Maths Part 2 Chapter 1 in Ganita Prakash. Important Questions Class 8 Maths Part 2 Chapter 1 cover fractions, decimals, percentages, profit and loss, discount, GST, simple interest, compound interest, and tricky percentage applications.
A 25% discount, 18% GST, 10% yearly interest, and 50% profit margin all use the same idea: a fraction written in another form. Class 8 Maths Chapter 1 Fractions in Disguise teaches students how to move between fractions, decimals, and percentages. The chapter becomes easier when students learn the base value first. Once the base is clear, profit, loss, discount, interest, and percentage increase questions become direct.
Key Takeaways
| Detail |
Information |
| Chapter |
Class 8 Maths Part 2 Chapter 1 |
| Topic |
Fractions in Disguise |
| Book |
Ganita Prakash Class 8 Part 2 |
| Syllabus |
NCERT 2026-27 |
| Question Types |
MCQ, short answer, application, worksheet-style, case-based |
| Key Topics |
FDP trio, percentages, profit and loss, discount, GST, SI, CI |
Class 8 Maths Chapter 1 Fractions in Disguise: Topics Covered
Before solving this chapter, identify the base quantity. In percentage questions, the same number can change meaning when the base changes.
- Fractions as percentages
- Decimals as percentages
- FDP trio: fractions, decimals, percentages
- Percentage of a quantity
- Percentages greater than 100
- Profit and loss
- Discount and marked price
- GST and taxes
- Simple interest
- Compound interest
- Successive percentage changes
- Tricky percentage questions
Important Questions for Class 8 Maths Chapter 1 with Answers
Important questions for Class 8 Maths Chapter 1 should be solved in order. Start with FDP conversions, then move to percentages, profit-loss, and interest.
These fraction in disguise class 8 important questions with answers are arranged by concept so students can practise every type of question clearly.

Fractions in Disguise Class 8 Questions on FDP Conversion
FDP means fractions, decimals, and percentages. This is the base skill for the full chapter.
If students can convert between these three forms quickly, most percentage class 8 maths questions become easier.
Fractions Decimals Percentages Class 8 Questions
Q1. Express the following fractions as percentages:
(i) 3/5
(ii) 7/14
(iii) 9/20
(iv) 72/150
(v) 1/3
(vi) 5/11
Ans.
(i) 3/5 × 100 = 60%
(ii) 7/14 = 1/2 = 50%
(iii) 9/20 × 100 = 45%
(iv) 72/150 × 100 = 48%
(v) 1/3 × 100 = 33.33% or 33⅓%
(vi) 5/11 × 100 = 45.45% approximately
Q2. Nandini has 25 marbles. 15 are white. What percentage of her marbles are white?
Ans.
Percentage = 15/25 × 100
Percentage = 60%
So, 60% of the marbles are white.
Q3. In a school, 15 of 80 students come by walking. What percentage of students walk to school?
Ans.
Percentage = 15/80 × 100
Percentage = 18.75%
Q4. Write the correct symbol: >, <, or =.
(i) 50% ___ 5%
(ii) 5/10 ___ 50%
(iii) 3/11 ___ 61%
(iv) 30% ___ 1/3
Ans.
(i) 50% > 5%
(ii) 5/10 = 50%
(iii) 3/11 = 27.27%, so 3/11 < 61%
(iv) 1/3 = 33.33%, so 30% < 1/3
Q5. Complete the FDP trio table.
| Percent |
Fraction |
Decimal |
| 50% |
1/2 |
0.5 |
| 25% |
1/4 |
0.25 |
| 75% |
3/4 |
0.75 |
| 10% |
1/10 |
0.1 |
| 1% |
1/100 |
0.01 |
| 5% |
1/20 |
0.05 |
| 100% |
1 |
1.0 |
Percentage Class 8 Maths Questions
Percentage questions depend on the word “of.” In maths, “of” usually means multiplication.
Find the base value first. Then convert the percentage into a fraction or decimal before multiplying.
Percentage of a Quantity Questions
Q1. Find the value of the following:
(i) 25% of 160
(ii) 16% of 250
(iii) 62% of 360
(iv) 140% of 40
(v) 1% of 1 hour
(vi) 7% of 10 kg
Ans.
(i) 25% of 160 = 25/100 × 160 = 40
(ii) 16% of 250 = 16/100 × 250 = 40
(iii) 62% of 360 = 62/100 × 360 = 223.2
(iv) 140% of 40 = 140/100 × 40 = 56
(v) 1% of 1 hour = 1/100 × 60 minutes = 0.6 minutes
(vi) 7% of 10 kg = 7/100 × 10 = 0.7 kg
Q2. 30% of k is 70. Find 60%, 90%, and 120% of k.
Ans.
30% of k = 70
60% is double of 30%.
So, 60% of k = 140.
90% is three times 30%.
So, 90% of k = 210.
120% is four times 30%.
So, 120% of k = 280.
Q3. 100% of m is 215. Find 10%, 1%, and 6% of m.
Ans.
10% of m = 215 ÷ 10 = 21.5
1% of m = 215 ÷ 100 = 2.15
6% of m = 6 × 2.15 = 12.9
Q4. Fill in the blanks.
(i) 3 is ___% of 300.
(ii) ___ is 40% of 4.
(iii) 40 is 80% of ___.
Ans.
(i) 3/300 × 100 = 1%
(ii) 40/100 × 4 = 1.6
(iii) 40 = 80/100 × x, so x = 50
Q5. Is 10% of a day longer than 1% of a week?
Ans.
10% of a day = 10/100 × 24 hours = 2.4 hours
1% of a week = 1/100 × 7 × 24 hours = 1.68 hours
Since 2.4 > 1.68, 10% of a day is longer.
Q6. The maximum marks in a test are 75. Students scoring 80% or above get an A grade. What is the minimum score Zubin needs?
Ans.
Minimum score = 80% of 75
= 80/100 × 75
= 60 marks
Q7. A cyclist completes 40% of the Delhi-Agra journey and has covered 92 km. How many kilometres are left?
Ans.
40% of total distance = 92 km
Total distance = 92 × 100/40
= 230 km
Remaining distance = 230 - 92
= 138 km
Percentages Greater Than 100 Questions
A percentage greater than 100 means the new value is more than the original value.
In this section of ganita prakash class 8 part 2 chapter 1, students must avoid treating 150% as 150. It means 1.5 times the base.
Ganita Prakash Class 8 Part 2 Chapter 1 Questions
Q1. Kishanlal’s daily sales target is Rs. 5000. His Day 7 sales were 150% of target and Day 8 sales were 210% of target. Find both sales.
Ans.
Day 7 sales = 150/100 × 5000
= Rs. 7500
Day 8 sales = 210/100 × 5000
= Rs. 10,500
Q2. A farmer harvested 260 kg wheat last year and 650 kg this year. What percentage of last year’s harvest is this year’s harvest?
Ans.
Percentage = 650/260 × 100
= 250%
This year’s harvest is 250% of last year’s harvest.
Q3. The population of Bengaluru in 2025 is about 250% of its population in 2000. If the population in 2000 was 50 lakhs, find the 2025 population.
Ans.
Population in 2025 = 250/100 × 50 lakhs
= 125 lakhs
Q4. The price of a mobile phone is Rs. 8250. GST of 18% is added. Find the final price.
Ans.
GST = 18% of 8250
= 18/100 × 8250
= Rs. 1485
Final price = 8250 + 1485
= Rs. 9735
Profit and Loss Class 8 Questions
Profit and loss class 8 questions depend on cost price, selling price, marked price, discount, and percentage.
Always check the base. Profit and loss are calculated on cost price. Discount is calculated on marked price.
Profit, Loss and Discount Questions
Q1. A shopkeeper buys a geometry box for Rs. 75 and sells it for Rs. 110. Find the profit percentage.
Ans.
Profit = 110 - 75
= Rs. 35
Profit % = 35/75 × 100
= 46.67%
Q2. A carpenter makes chairs. Cost of materials is Rs. 475 and desired profit margin is 50%. Find the selling price.
Ans.
Profit = 50% of 475
= 50/100 × 475
= Rs. 237.50
Selling price = 475 + 237.50
= Rs. 712.50
Q3. A clothing shop offers 25% discount on a shirt marked Rs. 300. How much will Anwar pay?
Ans.
Discount = 25% of 300
= Rs. 75
Selling price = 300 - 75
= Rs. 225
Q4. Samson bought a car for Rs. 4,40,000 after a 15% discount. Find the original price.
Ans.
Selling price = 85% of marked price
4,40,000 = 85/100 × marked price
Marked price = 4,40,000 × 100/85
= Rs. 5,17,647 approximately
Q5. Rice was purchased at Rs. 35 per kg. Raghu sells 10 kg for Rs. 300. Find the loss percentage.
Ans.
Cost price of 10 kg = 35 × 10
= Rs. 350
Selling price = Rs. 300
Loss = 350 - 300
= Rs. 50
Loss % = 50/350 × 100
= 14.28% approximately
Q6. Shyamala bought vases at Rs. 2650 each. She sells one damaged vase at 18% loss. Find the selling price.
Ans.
Loss = 18% of 2650
= 18/100 × 2650
= Rs. 477
Selling price = 2650 - 477
= Rs. 2173
Q7. A shopkeeper sets a price with 35% profit margin and then offers 30% discount. Will he make profit or loss?
Ans.
Let cost price = Rs. 100.
Marked price after 35% profit = Rs. 135
Selling price after 30% discount = 70% of 135
= 70/100 × 135
= Rs. 94.50
Since selling price is less than cost price, he makes a loss of Rs. 5.50.
Loss % = 5.5%
Q8. A store offers two options: 20% discount or Rs. 50 discount on purchases above Rs. 150. Which is better for Rs. 180, Rs. 225, and Rs. 300?
Ans.
For Rs. 180:
20% discount = Rs. 36
Rs. 50 discount is better.
For Rs. 225:
20% discount = Rs. 45
Rs. 50 discount is better.
For Rs. 300:
20% discount = Rs. 60
20% discount is better.
Simple Interest and Compound Interest Class 8 Questions
Simple interest and compound interest class 8 questions test whether interest is calculated on the original principal or on the updated amount.
Simple interest uses the same principal every year. Compound interest adds interest to the principal before the next year begins.
Interest Questions from Fractions in Disguise Class 8 Solutions
Q1. A bank offers 10% per annum. Compare what one gets if Rs. 20,000 is deposited for 2 years with and without compounding.
Ans.
Without compounding:
SI = P × R × T / 100
= 20000 × 10 × 2 / 100
= Rs. 4000
Total amount = Rs. 24,000
With compounding:
Year 1 interest = 10% of 20,000
= Rs. 2000
Amount after Year 1 = Rs. 22,000
Year 2 interest = 10% of 22,000
= Rs. 2200
Amount after Year 2 = Rs. 24,200
Compound interest gives Rs. 200 more.
Q2. The population of a city rises by 3% every year. Current population is 1.5 crore. Find the expected population after 3 years.
Ans.
Population after 3 years = 1.5 × (1.03)³ crore
= 1.5 × 1.092727
= 1.639 crore approximately
Q3. Bacteria increase at 2.5% per hour. Initial count is 5,06,000. Find the count after 2 hours.
Ans.
Count after 2 hours = 5,06,000 × (1.025)²
= 5,06,000 × 1.050625
= 5,31,616 approximately
Q4. A TV bought for Rs. 21,000 depreciates by 5% after one year. Find its value.
Ans.
Value after 1 year = 21,000 × (1 - 0.05)
= 21,000 × 0.95
= Rs. 19,950
Q5. Jasmine invests amount p for 4 years at 6% per annum without compounding. Write the expression for total amount.
Ans.
Without compounding, interest = p × 0.06 × 4
Total amount = p + (p × 0.06 × 4)
Q6. Bus fare increased 3% last year and 4% this year. Find the overall increase.
Ans.
Overall factor = 1.03 × 1.04
= 1.0712
Overall increase = 1.0712 - 1
= 0.0712
= 7.12%
The increase is 7.12%, not 7%, because the changes are successive.
Fractions in Disguise Class 8 Extra Questions
Fractions in disguise class 8 extra questions test whether students understand the base value in each percentage.
Use small assumed values like 100 when the actual value is not given.
Class 8 Maths Extra Questions Chapter 1
Q1. Surbhi kept a 50% profit margin and then offered 50% discount. Did she make any loss?
Ans.
Let cost price = Rs. 100.
Marked price after 50% profit = Rs. 150
Selling price after 50% discount = Rs. 75
Since Rs. 75 is less than Rs. 100, she made a loss.
Loss = Rs. 25
Loss % = 25%
Q2. What is 5% of 40? What is 40% of 5? What do you notice?
Ans.
5% of 40 = 5/100 × 40 = 2
40% of 5 = 40/100 × 5 = 2
Both are equal.
In general, x% of y = y% of x.
Q3. If the length of a rectangle increases by 10% and area remains unchanged, by what percentage does breadth decrease?
Ans.
Let original length = L and breadth = B.
New length = 1.1L
Area unchanged:
1.1L × new breadth = L × B
New breadth = B / 1.1
= 10B/11
Decrease = B - 10B/11
= B/11
Percentage decrease = (B/11)/B × 100
= 100/11%
= 9 1/11%
Q4. In a room of 100 people, 99% are left-handed. How many left-handed people must leave to make it 98%?
Ans.
Currently, 99 out of 100 people are left-handed.
Let x left-handed people leave.
Left-handed people left = 99 - x
Total people left = 100 - x
(99 - x)/(100 - x) = 98/100
99 - x = 98 - 0.98x
1 = 0.02x
x = 50
So, 50 left-handed people must leave.
Q5. Three shops sell the same item at Rs. 100. Shop A gives buy 1 get 1 free. Shop B gives buy 2 get 1 free. Shop C gives buy 3 get 1 free. Find effective price and discount percentage.
Ans.
Shop A:
Pay Rs. 100 for 2 items.
Effective price = Rs. 50
Discount = 50%
Shop B:
Pay Rs. 200 for 3 items.
Effective price = Rs. 66.67
Discount = 33.33%
Shop C:
Pay Rs. 300 for 4 items.
Effective price = Rs. 75
Discount = 25%
Cheapest order: A, B, C.
Q6. A school excursion has 40% Grade 8 and 60% Grade 9 students. Among Grade 8 students, 60% are girls. Total students = 160. Find the percentage and number of Grade 8 girls.
Ans.
Grade 8 girls = 60% of 40%
= 0.6 × 0.4
= 0.24
= 24% of total students
Number of Grade 8 girls = 24% of 160
= 24/100 × 160
= 38.4
So, approximately 38 students are Grade 8 girls.
Fractions in Disguise Class 8 Worksheet Practice
A fractions in disguise class 8 worksheet should mix direct conversions, word problems, commercial maths, and tricky percentages.
Do not solve only formula-based questions. This chapter is application-heavy.
Worksheet-Style Maths Questions for Class 8 with Answers
Q1. Convert 0.35 into a percentage.
Ans. 0.35 × 100 = 35%
Q2. Convert 12.5% into a fraction.
Ans. 12.5% = 12.5/100 = 125/1000 = 1/8
Q3. Find 30% of Rs. 450.
Ans. 30/100 × 450 = Rs. 135
Q4. A jacket marked Rs. 2000 is sold at 15% discount. Find the selling price.
Ans.
Discount = 15% of 2000
= Rs. 300
Selling price = 2000 - 300
= Rs. 1700
Q5. A bag is sold for Rs. 840 after 20% loss. Find the cost price.
Ans.
Selling price = 80% of cost price
840 = 80/100 × CP
CP = 840 × 100/80
= Rs. 1050
Q6. Find the amount on Rs. 5000 at 8% simple interest for 2 years.
Ans.
SI = P × R × T / 100
= 5000 × 8 × 2 / 100
= Rs. 800
Amount = 5000 + 800
= Rs. 5800
Important MCQs for Class 8 Maths Chapter 1 Fractions in Disguise
MCQs in this chapter often test quick conversion and common traps.
Read the base carefully before choosing the option.
Q1. Percentages are fractions with denominator:
(a) 10
(b) 50
(c) 100
(d) 1000
Ans. (c) 100
Q2. 1% of 1 hour in minutes is:
(a) 1 minute
(b) 0.6 minutes
(c) 60 minutes
(d) 10 minutes
Ans. (b) 0.6 minutes
Q3. If selling price is more than cost price, the result is:
(a) Loss
(b) Profit
(c) Discount
(d) Tax
Ans. (b) Profit
Q4. Surbhi kept a 50% margin and then gave a 50% discount. She had:
(a) No loss
(b) 25% loss
(c) 50% profit
(d) 100% profit
Ans. (b) 25% loss
Q5. The population of elephants increased by 5%. If the population last decade was p, the population now is:
(i) p × 0.5
(ii) p × 0.05
(iii) p × 1.5
(iv) p × 1.05
Ans. (iv) p × 1.05
Q6. “The demand for cameras has fallen by 85%” means:
(i) Demand now is 85% of earlier demand
(ii) Demand now is 15% of earlier demand
(iii) Earlier demand was 185% of current demand
Ans. (ii) Demand now is 15% of earlier demand
Q7. A “30% + 20% discount” is:
(a) Same as 50%
(b) Less than 50%
(c) More than 50%
(d) Zero
Ans. (b) Less than 50%
Successive discount = 1 - (0.7 × 0.8)
= 1 - 0.56
= 44%
Ganita Prakash Part 2 Chapter 1 Solutions: Common Question Types
Ganita Prakash Part 2 Chapter 1 solutions often require more than direct formula use. Students must identify whether the question uses percentage increase, decrease, discount, interest, or profit.
This is why writing the base value is the first step in every solution.
Class 8 Maths Ganita Prakash Solutions Practice
Q1. How do you identify the base in a percentage question?
Ans. The base is the original quantity or the quantity after the word “of.”
For example, in 25% of 400, the base is 400.
Q2. Why are successive discounts not added directly?
Ans. Each discount is applied to a new reduced price.
A 30% discount followed by 20% discount is not 50%. It is 44%.
Q3. Why does compound interest grow faster than simple interest?
Ans. In compound interest, each year’s interest is added to the principal.
The next interest is calculated on the increased amount.
All Key Formulas from Class 8 Maths Chapter 1
| Concept |
Formula |
| Fraction to percentage |
Fraction × 100 |
| Percentage of a quantity |
Percent/100 × Quantity |
| Profit |
SP - CP |
| Loss |
CP - SP |
| Profit % |
Profit/CP × 100 |
| Loss % |
Loss/CP × 100 |
| SP with profit |
CP × (1 + Profit%/100) |
| SP with loss |
CP × (1 - Loss%/100) |
| Discount |
MRP - SP |
| Discount % |
Discount/MRP × 100 |
| Simple Interest |
P × R × T / 100 |
| Amount after 1 year CI |
P × (1 + R/100) |
| Amount after n years CI |
P × (1 + R/100)^n |
| Percentage increase |
Increase/Original × 100 |
| Percentage decrease |
Decrease/Original × 100 |