Chapter 16 Playing with Numbers
Chapter 16 Playing with Numbers Very Short Answer Type Question 1. Write the following numbers in generalised form. (a) ab (b) 85 (c) 132 (d) 1000 Solution: (a) ab = 10 × a + 1 × b = 10a + b (b) 85 = 10 × 8 + 1 × 5 = 10 × 8 […]
Chapter 16 Playing with Numbers Exercise 16.2
Chapter 16 Playing with Numbers Exercise 16.2 Question 1. If 21y5 is a multiple of 9, where y is a digit, what is the value of y? Solution: A number is divisible by 9 if the sum of its digits is also divisible by 9. Sum of the digits of 21y5 = 2 + 1 […]
Chapter 16 Playing with Numbers Exercise 16.1
Chapter 16 Playing with Numbers Exercise 16.1 Find the values of the letters in each of the following and give reasons for the steps involved. Question 1. Solution: Question 2. Solution: Question 3. Solution: Question 4. Solution: Question 5. Solution: 3 × B = B ⇒ B = D 3 × A = CA ⇒ […]
Chapter 15 Introduction to Graphs
Chapter 15 Introduction to Graphs Question 1. Write the coordinates of each point shown is the graph. Solution: Question 2. From the given figure, choose the letters indicate the location of the points. (i) (3, 1) (ii) (0, 5) (iii) (3, 0) (iv) (1, 2) (v) (2, 3) (vi) (8, 12) (vii) (6, 10) (viii) […]
Chapter 15 Introduction to Graphs Exercise 15.3
Chapter 15 Introduction to Graphs Exercise 15.3 Question 1. Draw the graphs for the following tables of values, with suitable scales on the axes. (a) Cost of apples (b) Distance travelled by car. (i) How much distance did the car cover during the period 7:30 am to 8 am? (ii) What was the time when […]
Chapter 15 Introduction to Graphs Exercise 15.2
Chapter 15 Introduction to Graphs Exercise 15.2 Question 1. Plot the following points on a graph sheet. Verify if they lie on a line. (a) A (4, 0), B(4, 2), C(4, 6), D(4, 2.5) (b) P(1, 1), Q(2, 2), R(3, 3), S(4, 4) (c) K(2, 3), L(6, 3), M(5, 5), N (2, 5) Solution: Yes, […]
Chapter 15 Introduction to Graphs Exercise 15.1
Chapter 15 Introduction to Graphs Exercise 15.1 Question 1. The following graph shows the temperature of a patient in a hospital, recorded every hour. (a) What was the patient’s temperature at 1 pm? (b) When was the patient’s temperature 38.5°C? (c) The patient’s temperature was the same two times during the period given. What were […]
Chapter 14 Factorisation
Chapter 14 Factorisation Very Short Answer Type Question 1. Find the common factors of the following terms. (a) 25x2y, 30xy2 (b) 63m3n, 54mn4 Solution: (a) 25x2y, 30xy2 25x2y = 5 × 5 × x × x × y 30xy2 = 2 × 3 × 5 × x × y × y Common factors are 5× x […]
Chapter 14 Factorisation Exercise 14.3
Chapter 14 Factorisation Exercise 14.3 Question 1. Carry out the following divisions. (i) 28×4 ÷ 56x (ii) -36y3 ÷ 9y2 (iii) 66pq2r3 ÷ 11qr2 (iv) 34x3y3z3 ÷ 51xy2z3 (v) 12a8b8 ÷ (-6a6b4) Solution: Question 2. Divide the following polynomial by the given monomial. (i) (5×2 – 6x) ÷ 3x (ii) (3y8 – 4y6 + 5y4) ÷ y4 (iii) 8(x3y2z2 + x2y3z2 + x2y2z3) ÷ 4x2y2z2 […]
Chapter 14 Factorisation Exercise 14.2
Chapter 14 Factorisation Exercise 14.2 Question 1. Factorise the following expressions. (i) a2 + 8a +16 (ii) p2 – 10p + 25 (iii) 25m2 + 30m + 9 (iv) 49y2 + 84yz + 36z2 (v) 4×2 – 8x + 4 (vi) 121b2 – 88bc + 16c2 (vii) (l + m)2 – 4lm. (Hint: Expand (l + m)2 first) (viii) a4 + 2a2b2 + b4 Solution: […]