Chapter 2 Linear Equations in One Variable Exercise 2.3
Chapter 2 Linear Equations in One Variable Exercise 2.3 Question 1. 3x = 2x + 18 Solution: We have 3x = 2x + 18 ⇒ 3x – 2x = 18 (Transposing 2x to LHS) ⇒ x = 18 Hence, x = 18 is the required solution. Check: 3x = 2x + 18 Putting x = […]
Chapter 2 Linear Equations in One Variable Exercise 2.2
Chapter 2 Linear Equations in One Variable Exercise 2.2 Solution: Let the required number be x. Question 2. The perimeter of a rectangular swimming pool is 154 m. Its length is 2 m more than twice its breadth. What are the length and the breadth of the pool? Solution: Let the breadth of the pool […]
Chapter 2 Linear Equations in One Variable Exercise 2.1
Chapter 2 Linear Equations in One Variable Exercise 2.1 Question 1. Solve the equation: x – 2 = 7. Solution: Given: x – 2 = 7 ⇒ x – 2 + 2 = 7 + 2 (adding 2 on both sides) ⇒ x = 9 (Required solution) Question 2. Solve the equation: y + 3 […]
Chapter 1 Rational Numbers
Chapter 1 Rational Numbers Extra Questions Very Short Answer Type Question 1. Question 4. Question 5. What is the multiplicative identity of rational numbers? Solution: 1 is the multiplicating identity of rational numbers. Question 6. What is the additive identity of rational numbers? Solution: 0 is the additive identity of rational numbers. Solution: Short Answer […]
Chapter 1 Rational Numbers Exercise 1.2
Chapter 1 Rational Numbers Exercise 1.2 Question 1. Represent these numbers on the number line Question 2. Solution: Question 5. Find five rational numbers between Solution: Question 6. Question 7.
Chapter 1 Rational Numbers Exercise 1.1
Chapter 1 Rational Numbers Exercise 1.1 Question 1. Using appropriate properties find: Solution: Question 2. Write the additive inverse of each of the following: Solution: Question 3. Verify that -(-x) = x for Solution: Question 4. Find the multiplicative inverse of the following: Solution: Question 5. Name the property under multiplication used in each of […]
Chapter 13 Sound
Chapter 13 Sound Textbook Questions Question 1. Choose the correct answer. Sound can travel through (a) gases only (b) solids only (c) liquids only (d) solids, liquids, and gases Answer: (d) solids, liquids, and gases. Question 2. Voice of which of the following is likely to have a minimum frequency? (a) Baby girl (b) Baby […]
Chapter 18 Pollution of Air And Water
Chapter 18 Pollution of Air And Water Textbook Questions Question 1. What are the different ways in which water gets contaminated? Answer: Following are the ways by which water gets contaminated: People dispose of garbage in the water. Many industries discharge their harmful chemicals directly into rivers and streams. Chemical fertilisers, pesticides and weedicides used […]
Chapter 17 Stars and The Solar System
Chapter 17 Stars and The Solar System Textbook Questions Choose the correct answer in Questions 1-3. Question 1. Which of the following is NOT a member of the solar system? (a) An asteroid (b) A satellite (c) A constellation (d) A comet Answer: (c) A constellation Question 2. Which of the following is NOT a […]
Chapter 16 Light
Chapter 16 Light Textbook Questions Question 1. Suppose you are in a dark room. Can you see objects in the room? Can you see objects out¬side the room? Explain. Answer: When we are in a dark room then we cannot see objects in the room. We can see the objects outside the room, because out […]