Highest common factor of 85 and 185?

To find the highest common factor (HCF) of 85 and 185, we first need to factorize both numbers. The factors of 85 are 1, 5, 17, and 85. The factors of 185 are 1, 5, 37, and 185. The common factors are 1 and 5. Therefore, the highest common factor of 85 and 185 is 5.