What is the HCF of 42 154 and 168?

The Highest Common Factor (HCF) of 42, 154, and 168 is the largest positive integer that divides all three numbers without leaving a remainder. To find the HCF, you can first find the prime factorization of each number: 42 = 2 x 3 x 7, 154 = 2 x 7 x 11, and 168 = 2 x 2 x 2 x 3 x 7. Then, identify the common prime factors among the numbers and multiply them together to get the HCF. In this case, the HCF of 42, 154, and 168 is 2 x 7 = 14.