Three letters are chosen at random from the word "HEART" and arranged in a row. Find the probability that:

a. the letter H is firstSo, three letters are chosen randomly and arranged in a row. There are ways they can be arranged... Since you want the first letter to be a H, there is only one way that can happen, and there is ways that can happen. So

Letter H can now be in 1 of 3 places, sob. the letter H is chosen

So there is ways to arrange the 2 vowels, and the remaining 3 characters can be arranged in any of the 3 positions, so there are 9 ways for the other letter to be positioned.c. both vowels are chosen

So