NCERT Solutions for Class 8 Maths Chapter 8 Comparing Quantities InText Questions
NCERT Solutions for Class 8 Maths Chapter 8 Comparing Quantities InText Questions
These NCERT Solutions for Class 8 Maths Chapter 8 Comparing Quantities InText Questions and Answers are prepared by our highly skilled subject experts.
NCERT Solutions for Class 8 Maths Chapter 8 Comparing Quantities InText Questions
Try These (Page No. 119)
Question 1.
In a primary school, the parents were asked about the number of hours they spend per day in helping their children to do homework.
Using this, answer the following:
(i) How many parents were surveyed?
(ii) How many said that they did not help?
Solution:
30% [ surveyed parents] = 90
or 30/100 × [surveyed parents] = 90
or surveyed parents = 90 × 100/30
= 3 × 100
= 300
(ii) Since, 50% of surveyed parents did not help their children.
Number of parents who did not help = 50% of surveyed parents
= 50% of 300
= 50/100 × 300
= 150
= 20/100 × 300
= 20 × 3
= 60
Note: ‘of’ means multiplication
Try These (Page No. 121)
Question 2.
A shop gives a 20% discount. What would the sale price of each of these be?
(a) A dress marked at ₹ 120
(b) A pair of shoes marked at ₹ 750
(c) A bag marked at ₹ 250
Solution:
(a) Marked price of the dress = ₹ 120
Discount rate = 20%
Discount = 20% of ₹ 120
= ₹ 20/100 × 120
= ₹ 2 × 12
= ₹ 24
Sale price of the dress = [Marked Price] – [Discount]
= ₹ 120 – ₹ 24
= ₹ 96
(b) Marked price of the pair of shoes = ₹ 750
Discount rate = 20%
Discount = 20% of ₹ 750
= ₹ 20/100 × 750
= ₹ 2 × 75
= ₹ 150
Now, Sale price of the pair of shoes = [Marked Price] – [Discount]
= ₹ 750 – ₹ 150
= ₹ 600
(c) Marked price of the bag = ₹ 250
Discount rate = 20%
Discount = 20% of ₹ 250
= ₹ 20/100 × 250
= ₹ 2 × 25
= ₹ 50
Sale price of the bag = [Marked price] – [ Discount]
= ₹ 250 – ₹ 50
= ₹ 200
Question 3.
A table marked at ₹ 15,000 is available for ₹ 14,000. Find the discount given and the discount percent.
Solution:
The marked price of the table = ₹ 15000
Sale price of the table = ₹ 14400
Discount = [Marked Price] – [Sale price]
= ₹ 15000 – ₹ 14400
= ₹ 600
Discount percent = Discount/Marked Price × 100
Question 4.
An almirah is sold at ₹ 5,225 after allowing a discount of 5%. Find its marked price.
Solution:
Sale price of the almirah = ₹ 5255
Discount rate = 5%
Try These (Page No. 123)
Question 5.
Find selling price (SP) if a profit of 5% is made on
(a) a cycle of ₹ 700 with ₹ 50 as overhead charges.
(b) a lawnmower bought at ₹ 1150 with ₹ 50 as transportation charges.
(c) a fan bought for ₹ 560 and expenses of ₹ 40 made on its repairs.
Solution:
(a) Total cost price = ₹ 700 + ₹ 50 (overhead expenses) = ₹ 750
Now, SP = CP + profit
= ₹ 750 + ₹ 37.50
= ₹ 787.50
(b) Total cost price = ₹ 1150 + ₹ 50 (Overhead expenses) = ₹ 1200
Profit = 5% of 1200
= 5/100 × ₹ 1200
= ₹ 5 × 12
= ₹ 60
Now, SP = CP + Profit
= ₹ 1200 + ₹ 60
= ₹ 1260
(c) Total cost price = ₹ 560 + ₹ 40 (Overhead expenses) = ₹ 600
Profit = 5% of ₹ 600 = 5/100 × ₹ 600
= ₹ 5 × 6
= ₹ 30
Now, SP = CP + profit
= ₹ 600 + ₹ 30
= ₹ 630
Try These (Page No. 123)
Question 6.
A shopkeeper bought two TV sets at ₹ 10,000 each. He sold one at a profit of 10% and the other at a loss of 10%. Find whether he made an overall profit or loss.
Solution:
(a) Marked price of the dress = ₹ 120
Discount rate = 20%
Discount = 20% of ₹ 120
= ₹ 20/100 × 120
= ₹ 2 × 12
= ₹ 24
Sale price of the dress = [Marked Price] – [Discount]
= ₹ 120 – ₹ 24
= ₹ 96
(b) Marked price of the pair of shoes = ₹ 750
Discount rate = 20%
Discount = 20% of ₹ 750
= ₹ 20/100 × 750
= ₹ 2 × 75
= ₹ 150
Now, Sale price of the pair of shoes = [Marked Price] – [Discount]
= ₹ 750 – ₹ 150
= ₹ 600
(c) Marked price of the bag = ₹ 250
Discount rate = 20%
Discount = 20% of ₹ 250
= ₹ 20/100 × 250
= ₹ 2 × 25
= ₹ 50
Sale price of the bag = [Marked price] – [Discount]
= ₹ 250 – ₹ 50
= ₹ 200
Try These (Page No. 126)
Question 7.
Find the interest and amount to be paid on ₹ 15000 at 5% per annum after 2 years.
Solution:
Amount = ₹ 15000 + ₹ 1500 = ₹ 16,500
Try These (Page No. 129)
Question 8.
Find Cl on a sum of ₹ 8000 for 2 years at 5% per annum compounded annually.
Solution:
We have
Now, compound interest = A – P
= ₹ 8820 – ₹ 8000
= ₹ 820
Try These (Page No. 130)
Question 9.
Find the time period and rate for each.
Try These (Page No. 131)
Question 10.
Find the amount to be paid
1. At the end of 2 years on ₹ 2,400 at 5% per annum compounded annually.
2. At the end of 1 year on ₹ 1,800 at 8% per annum compounded quarterly.
Solution:
1. We have:
P = ₹ 2400, R = 5% p.a., T = 2 years
∴ Interest is compounded annually i.e, n = 2
2. Here, interest compounded quarterly.
R = 8%, p.a. = 8/4, i.e., 2% per quarter
T = 1 year = 4 × 1, i.e., 4 quarters on
n = 4
Try These (Page No. 133)
Question 11.
A machinery worth ₹ 10,500 depreciated by 5%. Find its value after one year?
Solution:
Here, P = 10, 500, R = 5% p.a.
Question 12.
Find the population of a city after 2 years, which is at present 12 lakh, if the rate of increase is 4%.
Solution:
Present population, P = 12 lakh
Rate of increase, R = 4% p.a.
Time, T = 2 years
n = 2
Thus, the population of the town will be 12,97,920 after 2 years.
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