![[Class 7 Maths] Find the common factors, and the HCF of 45 and 75. - Finding HCF using Prime Factorisation](https://cdn.teachoo.com/c77fa6c1-2b4b-4d7f-b6ea-4f7286c7b2ee/slide59.jpg)
Example 1 - Chapter 3 Class 7 - Finding Common Ground (Ganita Prakash II)
Last updated at January 22, 2026 by Teachoo
Finding HCF using Prime Factorisation
Finding HCF using Prime Factorisation
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Class 7 (Ganita Prakash 1, 2 & old NCERT)
Chapter 3 Class 7 - Finding Common Ground (Ganita Prakash II)
- The Greatest of All
- Prime Factorisation
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Finding HCF using Prime Factorisation
- Figure it out - Page 54
- Least, but not Last!
- Finding LCM using Prime Factorisation
- Patterns, Properties, and a Pretty Procedure!
- Figure it out - Page 59
- Miscellenaous Questions on HCF, LCM
- Efficient Procedures for HCF and LCM
- Property Involving both the HCF and the LCM
- Figure it out - Page 63, 64
Transcript
Example 1 Find the common factors, and the HCF of 45 and 75.Let’s find Prime Factorisation of both 45 & 75 Now, 45 = 3 × 3 × 5 75 = 3 × 5 × 5 HCF of 45, 75 = 3 × 5 = 15Now, we need to find Common Factors also Common Factors of 45 & 75 Since 45 = 3 × 3 × 5 75 = 3 × 5 × 5 The common factors are 3 5 And, 3 × 5 = 15 Thus, common factors are 3, 5 and 15
