
### Instruction: help me answer this question How many 4-letter codes can be formed using the first 10 letters of the English alphabet, if no letter can be repeated?, think step by step
### Assistant: To find the total number of 4-letter codes, we need to find the number of possible digits for each place and multiply them together. Here, the number of possible digits for the first place is 10, for the second place is 9, for the third place is 8 and for the fourth place is 7. , The answer is 5040
