Here, we have to form a 5 letter code using first 6 letters of english alphabet such that no letter is letter repeated. No. of ways to choose 1st letter for the code = 6 No. of ways to choose 2nd letter for the code = 5 No. of ways to choose 3rd letter for the code = 4 No. of ways to choose 4th letter for the code = 3 No. of ways to choose 5th letter for the code = 2 ∴ The no. of ways to form a 5 letter code using first 6 letters of english alphabet = 6 × 5 × 4 × 3 × 2 = 720.