HCF and LCM Examples Example 1: Find the Highest Common Factor of 25, 35 and 45. Solution: Given, three numbers as 25, 35 and 45. We know, 25 = 5 × 5 35 = 5 × 7 45 = 5 × 9 From the above expression, we can say 5 is the only common factor for all three numbers. ...