Students can Download Class 8 Maths Chapter 9 Commercial Arithmetic Ex 9.1 Questions and Answers, Notes Pdf, KSEEB Solutions for Class 8 Maths helps you to revise the complete Karnataka State Board Syllabus and to clear all their doubts, score well in final exams.

## Karnataka State Syllabus Class 8 Maths Chapter 9 Commercial Arithmetic Ex 9.1

Question 1.

In a school 30% students play chess 60% play carrom and the rest play other games. If the total number of students in the school is 900 find the exact number of students who play each game.

Answer:

30% Students play chess. Total number of students is 900.

The number of players who play chess = 30% of 900.

= \(\frac { 300 }{ 100 }\) × 900 = 270

The number of players who play carrom board = 60% of 900

= \(\frac { 60}{ 100 }\) × 900 = 540

The number of players who play other games = 10% of 900

= \(\frac { 10 }{ 100 }\) × 900 = 90

Question 2.

In a school function ₹ 360 remained after spending 82% of the money. How much money was there in the beginning? verify your answer.

Answer:

Let the money, in the beginning, be Rs. 100 The money spent is Rs. 82.

∴ The amount remaining is 100 – 82=Rs. 18.

If the remaining money is Rs. 18 the money, in the beginning, is Rs. 100.

If the remaining money is Rs. 360 the money in the beginning is

= \(\frac { 100 }{ 18 }\) × 360 = 2000

Verification :

\(\frac { 82}{ 100 }\) × 2000 = 1640

Money remained = 2000 – 1640 = Rs. 360.

Question 3.

Akshay’s income is 20% less than that of Ajay what percent is Ajay’s income more than that of Akshay?

Answer:

Let Ajay’s income be ₹ 100.

Then Akshay’s income is (100 – 20) = ₹ 80.

If Akshay’s income is ₹ 80.

Ajay’s income is ₹ 100.

If Akshay’s income is ₹ 1 Ajay’s income is

× 1 = ₹

Changing the scale to 100.

Ajay’s income is ₹ 100

Akshay’s income is

= × 100 = 125

∴ Ajay’s income is 125 – 100 = 25% more than that of Akshay.

Question 4.

A daily wage employee spends 84% of his weekly earning. If he saves ₹ 384 find his weekly earning.

Answer:

Let his weekly earning be Rs. 100.

His expenditure is Rs. 84.

Therefore his savings is (100 – 84) = Rs. 16

If the savings is Rs. 16 then the income is Rs. 100.

If the savings is Rs. 384 then the income is

= \(\frac { 100 }{ 16 }\) × 384 = Rs.2400

∴ His weekly earning is Rs. 2400.

Question 5.

A factory announces a bonus of 10% of its employees. If an employee gets ₹ 10,780 find his actual salary.

Answer:

Let the salary of the employee be Rs. 100.

He gets a bonus of Rs. 10.

He gets 100 + 10 = Rs. 110 including bonus.

∴ If the employee gets Rs. 10.780 his salary is

= \(\frac { 100 }{ 110 }\) × 10780 = 9800

∴ The salary of the employee is Rs. 9800