How many diffrent three letter permutation can be formed from letter in the word decagon

210

Step-by-step explanation:

Lets look at the three letter permutation. For the first letter, you have 7 different options (each of the 7 letters can start the word). However, per the question, each letter can only be used once. Thus, the next letter can only be one of 6 remaining letters. The final one will be one of the remaining 5. Thus, the number of permutations is 7 * 6 * 5.