Which of the following pairs of numbers are co-prime? (a) 18 and 35 - Co-prime numbers (and art)

part 2 - Example 1 (Page 116) - Co-prime numbers (and art) - Chapter 5 Class 6 - Prime Time (Ganita Prakash) - Class 6 (Ganit Prakash)
part 3 - Example 1 (Page 116) - Co-prime numbers (and art) - Chapter 5 Class 6 - Prime Time (Ganita Prakash) - Class 6 (Ganit Prakash)
part 4 - Example 1 (Page 116) - Co-prime numbers (and art) - Chapter 5 Class 6 - Prime Time (Ganita Prakash) - Class 6 (Ganit Prakash)
part 5 - Example 1 (Page 116) - Co-prime numbers (and art) - Chapter 5 Class 6 - Prime Time (Ganita Prakash) - Class 6 (Ganit Prakash) part 6 - Example 1 (Page 116) - Co-prime numbers (and art) - Chapter 5 Class 6 - Prime Time (Ganita Prakash) - Class 6 (Ganit Prakash)

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Example 1 (Page 116) Which of the following pairs of numbers are co-prime? (a) 18 and 35 Factors of 18 1 × 18 = 18 2 × 9 = 18 3 × 6 = 18 6 × 3 = 18 We stop here as 3 & 6 have occurred earlier So factors of 18 are 1, 2, 3, 6, 9, and 18 Factors of 35 1 × 35 = 35 5 × 7 = 35 7 × 5 = 35 We stop here as 7 and 5 have occurred earlier So factors of 35 are 1, 5, 7, 35 Example 1 (Page 116) Which of the following pairs of numbers are co-prime? (b) 15 and 37 Factors of 15 1 × 15 = 15 3 × 5 = 15 5 × 3 = 15 We stop here as 5 & 3 have occurred earlier So factors of 15 are 1, 3, 5, 15 Factors of 37 1 × 37 = 37 37 × 1 = 37 We stop here as 37 and 1 have occurred earlier So factors of 37 are 1, 37 Since common factor is 1, They are co-prime numbers Example 1 (Page 116) Which of the following pairs of numbers are co-prime? (c) 30 and 415 Factors of 30 1 × 30 = 30 2 × 15 = 30 3 × 10 = 30 5 × 6 = 30 6 × 5 = 30 We stop as 6 & 5 have occurred earlier So factors of 30 are 1, 2, 3, 5, 6, 10, 15, 30 Factors of 415 1 × 415 = 415 5 × 83 = 415 83 × 5 = 415 We stop here as 83 and 5 have occurred earlier So factors of 415 are 1, 5, 83, 415 So, common factors are 1, 5 Since common factors are other than 1, They are not co-prime numbers Example 1 (Page 116) Which of the following pairs of numbers are co-prime? (d) 17 and 69 Factors of 17 1 × 17 = 17 17 × 1 = 17 We stop as 1 & 17 have occurred earlier So, factors of 17 are 1 and 17 Factors of 69 1 × 69 = 69 3 × 23 = 69 23 × 3 = 69 We stop as 23 and 3 have occurred earlier So factors of 69 are 1, 3, 23, 69 Example 1 (Page 116) Which of the following pairs of numbers are co-prime? (f) 81 and 18 Factors of 81 1 × 81 = 81 3 × 27 = 81 9 × 9 = 81 27 × 3 = 81 We stop as 3 & 27 have occurred earlier Factors of 81 are 1, 3, 9, 27, 81 Factors of 18 1 × 18 = 18 2 × 9 = 18 3 × 6 = 18 6 × 3 = 18 We stop here as 6 and 3 have occurred earlier Factors of 18 are 1, 2, 3, 6, 9, 18

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 15 years. He provides courses for Maths, Science and Computer Science at Teachoo