## ML Aggarwal Class 8 Solutions for ICSE Maths Chapter 7 Percentage Check Your Progress

Question 1.

Convert \(\frac{7}{24}\) into a percentage correct to foursignificant figures.

Solution:

Question 2.

Express 750 mL as a percentage of 4 litres.

Solution:

Required Percentage

Question 3.

A football team won 9 matches out of the total number of matches they played. If their win percentage was 45, then how many matches did they play in all?

Solution:

Let total matches = x

Matches won by a team = 9

Percentage = 45%

45% of x = 9

x= \(\frac{9 \times 100}{45}\) =20

∴ No. of matches played = 20

Question 4.

In a straight student election, Rahul got 66% of the votes polled. If the defeated student got 187 votes, find the total number of votes polled.

Solution:

Rahul got votes in student election = 66%

Defeated student got votes = (100 – 66%) = 34%

Let the total number of votes = x

According to given,

34% of x = 187

Hence total number of votes = 550

Question 5.

36 kg of gunpowder contains 27 kg nitre, 5.4 kg charcoal and rest sulphur. Find the percentage content of sulphur in the gunpowder.

Solution:

Total mixture of gunpowder = 36 kg

Quantity of nitre = 27 kg

Quantity of charcoal = 5.4 kg

Rest quantity of sulphur = 36 – (27 + 5.4)kg

= 36 – 32.4 = 3.6 kg

∴ Percentage of sulphur = \(\frac{3.6 \times 100}{36}\)% = 10%

Question 6.

75% of the students in a class passed an exam. If 2 more students had passed the exam. 80% would have been successful. How many students are there in the class ?

Solution:

Let the total number of students in the class be x,

Number of passed students in the class = 75% of x

Hence the total number of students in class = 40

Question 7.

The monthly salary of a school teacher in 2007 was ₹12000. It increased by 10% in 2008 and again by 10% in 2009. What is his salary in 2009?

Solution:

Total salary in 2007 = ₹ 12000

Increase in 2008 = 10%

and again increase in 2009 = 10%

∴ Salary in 2009

Question 8.

Price of a commodity decreased by 10% last year and increased by 20% this year. Find the percentage change in two years.

Solution:

Let the Price of commodity = ₹ x

When the price of commodity decreased by 10% in last year

Then Price of a commodity in Last year

When the price of commodity increased by 20% in this year

Then price of commodity in this year

Increased of price of commodity in these 2 years

% Increases of price of commodity in these 2 years

Question 9.

A shop gives 15% discount. What would the sale price of each of these be?

(i) A dress marked at ₹150

(ii) A pair of shoes marked at ₹800.

Solution:

Rate of discount = 15%

(i) A dress marked at ₹ 150

Question 10.

A refrigerator marked at ₹18000 is available for ₹17100. Find the discount given and the discount percent.

Solution:

Marked price of a regrigerator = ₹ 18000

Sale price = ₹17100

.∴ Discount = ₹18000 – ₹17100 = ₹900

Rate of discount =\(\frac{900 \times 100}{18000}\) = 5%

Question 11.

Ramu purchased 20 parrots at ₹30 each. Two parrots flew away and Ramu sold the rest of the parrots at ₹40 each. Calculate the profit or loss percentage of Ramu.

Solution:

C.P. of one parrot = ₹30

C.P. of 20 parrots = ₹30 × 20 = ₹600

The Number of parrots flew away = 2

Number of rest of the parrots = 20 – 2 = 18

Then S.P. of remaining parrots = ₹40 × 18 = ₹ 720

Profit = S.P. – C.P. = ₹720 – ₹600 = ₹120

Question 12.

Reena bought two tables for ₹ 1800 each. She sold one at a loss of 8% and the other at a profit of 12%. Find the selling price of each. Also, find out the total profit or loss.

Solution:

C.P. of one table = ₹1800

Loss = 8%

Question 13.

Ajit bought an old car ₹78000. He spent ₹2000 on repairs and repainting the car. He sold the car to Anju at a gain of 15%. Anju sold it to Anthony at a loss of 5%. What did the car cost to Anthony?

Solution:

C.P. of car = ₹78000

Money spent on repairs and repainting ₹2000

Total C.P. of car = ₹78000 + ₹2000 = ₹80000

Ajit sold the car to Anju at a gain of 15%

But this amount of car is C.P. for Anju.

∴ For Anju,

C.P. of Car = ₹92000

Loss = 5%

Hence the car cost to Anthony = ₹87400

Question 14.

Gaurav sold an article at a profit of 12%. Had it been sold for ₹16 more, the profit would have been 20%. Find the C.P. of the article.

Solution:

Let the cost price of the article = ₹x,

Profit = 12%

Hence the cost price of the article = ₹200

Question 15.

A shopkeeper allows 8% discount on his goods and still earns a profit of 15%. If an article is sold for ₹460, find :

(i) the marked price

(ii) the cost price.

Solution:

(i) Since the shopkeeper allows a discount of 8%

(ii) Let the cost price of the article be ₹x ;

Profit = 15%

Also, S.P. = ₹460

Hence, the cost price of the article = ₹400

Question 16.

Rajesh bought an A.C. for ₹38500 including 10% VAT. Find the price ofA.C. before VAT was added.

Solution:

Total C.P. of an A.C. = ₹38500

VAT = 10%

Original price of AC = ₹ \(\frac{38500 \times 100}{100+10 \%}\) = \(\frac{38500 \times 100}{110}\) = ₹35000

Question 17.

A DVD player is marked for ₹3000. The shopkeeper offers 10% discount on it. If VAT is received 8%. Find the amount paid by the customer.

Solution:

Marked price of a DVD player = ₹3000

Discount = 10%