Choose the first letter 3 ways, Choose the 2nd letter 9 ways. Choose the 3rd letter 8 ways. Choose the 4th letter 7 ways. Choose the 5th letter 6 ways. Choose the 6th letter 5 ways. Choose the 7th letter 4 ways. Choose the 8th letter 3 ways. Choose the 9th letter 2 ways. Choose the 10th letter 1 ways. 3×9×8×7×6×5×4×3×2×1 = 3×9! = 1088640 ways. Edwin