What are the highest common factors of 245 and 140?

To find the highest common factor (HCF) of 245 and 140, we need to determine the largest number that divides both 245 and 140 without leaving a remainder. The factors of 245 are 1, 5, 7, 35, 49, and 245. The factors of 140 are 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, and 140. The common factors of 245 and 140 are 1, 5, and 35. Therefore, the highest common factor of 245 and 140 is 35.