Answer:
1/720
Step-by-step explanation:
A through J is 10 letters. The probability of the first letter is 1/10, then H is 1/9 because there are 9 left, and D is 1/8, because there are 8 left. Since you will choose all 3 letters, you need to multiply the probabilities. Multiply to get 1/10*1/9*1/8 which is 1/720. Good luck!