Chapter 10 Visualising Solid Shapes Exercise 10.3
Chapter 10 Visualising Solid Shapes Exercise 10.3 Question 1. Can a polyhedron have for its faces (i) 3 triangles? (ii) 4 triangles? (iii) a square and four triangles? Solution: (i) No, because polyhedron must have edges meeting at vertices which are points. (ii) Yes, because all the edges are meeting at the vertices. (iii) Yes, […]
Chapter 10 Visualising Solid Shapes Exercise 10.2
Chapter 10 Visualising Solid Shapes Exercise 10.2 Question 1. Look at the given map of a city. Answer the following. (a) Colour the map as follows: Blue-water, red- fire station, orange-library, yellow-schools, Green-park, Pink-College, Purple-Hospital, Brown-Cemetery. (b) Mark a green ‘X’ at the intersection of Road ‘C’ and Nehru Road, Green ‘Y’ at the intersection […]
Chapter 10 Visualising Solid Shapes Exercise 10.1
Chapter 10 Visualising Solid Shapes Exercise 10.1 Question 1. For each of the given solid, the two views are given. Match for each solid the corresponding top and front views. The first one is done for you. Solution: (a) A bottle → (iii) → (iv) (b) A weight → (i) → (v) (c) A flask […]
Chapter 9 Algebraic Expressions and Identities
Chapter 9 Algebraic Expressions and Identities Very Short Answer Type Question 1. Write two examples of each of (i) Monomials (ii) Binomials (iii) Trinomials Solution: (i) Monomials: (a) 3x (b) 5xy2 (ii) Binomials: (a) p + q (b) -5a + 2b (iii) Trinomials: (a) a + b + c (b) x2 + x + 2 Question […]
Chapter 9 Algebraic Expressions and Identities Exercise 9.5
Chapter 9 Algebraic Expressions and Identities Exercise 9.5 Question 1. Use a suitable identity to get each of the following products: Solution: Question 2. Use the identity (x + a)(x + b) = x2 + (a + b)x + ab to find the following products. (i) (x + 3) (x + 7) (ii) (4x + 5)(4x […]
Chapter 9 Algebraic Expressions and Identities Exercise 9.4
Chapter 9 Algebraic Expressions and Identities Exercise 9.4 Solution: (i) (2x + 5) × (4x – 3) = 2x × (4x – 3) + 5 × (4x – 3) = (2x × 4x) – (3 × 2x) + (5 × 4x) – (5 × 3) = 8×2 – 6x + 20x – 15 = 8×2 + 14x […]
Chapter 9 Algebraic Expressions and Identities Exercise 9.3
Chapter 9 Algebraic Expressions and Identities Exercise 9.3 Question 1. Carry out the multiplication of the expressions in each of the following pairs: (i) 4p, q + r (ii) ab, a – b (iii) a + b, 7a2b2 (iv) a2 – 9, 4a (v) pq + qr + rp, 0 Solution: (i) 4p × (q + […]
Chapter 9 Algebraic Expressions and Identities Exercise 9.2
Chapter 9 Algebraic Expressions and Identities Exercise 9.2 Question 1. Find the product of the following pairs of monomials. (i) 4, 7p (ii) -4p, 7p (iii) -4p, 7pq (iv) 4p3, -3p (v) 4p, 0 Solution: (i) 4 × 7p = (4 × 7) × p = 28p (ii) -4p × 7p = (-4 × 7) […]
Chapter 9 Algebraic Expressions and Identities Exercise 9.1
Chapter 9 Algebraic Expressions and Identities Exercise 9.1 Question 1. Identify the terms, their coefficients for each of the following expressions. Solution: Question 2. Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories? x + y, 1000, x + + + , 7 + y […]
Chapter 8 Comparing Quantities
Chapter 8 Comparing Quantities Very Short Answer Type Solution: Question 3. If 20% of x is 25, then find x. Solution: 20% of x = 25 Hence x = 125 Question 4. Express the following as a fraction (a) 35% (b) 64% Solution: Hence, profit = 25% Question 8. An article is marked at ₹ […]