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 ₹ […]
Chapter 8 Comparing Quantities Exercise 8.3
Chapter 8 Comparing Quantities Exercise 8.3 Solution: (a) Given: P = ₹ 10,800, n = 3 years, CI = A – P = ₹ 70,304 – ₹ 62,500 = ₹ 7,804 Hence, amount = ₹ 70304 and CI = ₹ 7804 (d) Given: P = ₹ 8,000, n = 1 years R = 9% per […]
Chapter 8 Comparing Quantities Exercise 8.2
Chapter 8 Comparing Quantities Exercise 8.2 Question 1. A man got a 10% increase in his salary. If his new salary is ₹ 1,54,000, find his original salary. Solution: The increased salary = ₹ 1,54,000 Increase in salary = 10% Increase salary = Original salary × (1 + Increase100) Hence, the original salary = ₹ 1,40,000 […]
Chapter 8 Comparing Quantities Exercise 8.1
Chapter 8 Comparing Quantities Exercise 8.1 Question 1. Find the ratio of the following: (a) speed of a cycle 15 km per hour to the speed of scooter 30 km per hour. (b) 5 m to 10 km (c) 50 paise to ₹ 5 Solution: (a) Speed of cycle : Speed of Scooter = 15 […]
Chapter 7 Cubes and Cube Roots
Chapter 7 Cubes and Cube Roots Very Short Answer Type Question 2. Find the cubes of the following: (a) 0.3 (b) 0.8 (c) .001 (d) 2 – 0.3 Solution: Question 3. Is 135 a perfect cube? Solution: Prime factorisation of 135, is: 135 = 3 × 3 × 3 × 5 We find that on […]
Chapter 7 Cubes and Cube Roots Exercise 7.2
Chapter 7 Cubes and Cube Roots Exercise 7.2 Question 1. Find the cube root of each of the following numbers by prime factorisation method. (i) 64 (ii) 512 (iii) 10648 (iv) 27000 (v) 15625 (vi) 13824 (vii) 110592 (viii) 46656 (ix) 175616 (x) 91125 Solution: Question 2. State True or False. (i) Cube of an […]
Chapter 7 Cubes and Cube Roots Exercise 7.1
Chapter 7 Cubes and Cube Roots Exercise 7.1 Question 1. Which of the following numbers are not perfect cubes? (i) 216 (ii) 128 (iii) 1000 (iv) 100 (v) 46656 Solution: (i) Prime factorisation of 216 is: 216 = 2 × 2 × 2 × 3 × 3 × 3 In the above factorisation, 2 and 3 have formed […]
Chapter 6 Squares and Square Roots
Chapter 6 Squares and Square Roots Very Short Answer Type Question 1. Find the perfect square numbers between 40 and 50. Solution: Perfect square numbers between 40 and 50 = 49. Question 2. Which of the following 242, 492, 772, 1312 or 1892 end with digit 1? Solution: Only 492, 1312 and 1892 end with digit 1. Question 3. […]