Given the four digits 2, 4, 6, and 7, how many different positive three-digit integers can be formed using these digits if a digit may not be repeated in an integer?
4 P 3 = 4! = 24
{2, 4, 6} | {2, 4, 7} | {2, 6, 4} | {2, 6, 7} | {2, 7, 4} | {2, 7, 6} | {4, 2, 6} | {4, 2, 7} | {4, 6, 2} | {4, 6, 7} | {4, 7, 2} | {4, 7, 6} | {6, 2, 4} | {6, 2, 7} | {6, 4, 2} | {6, 4, 7} | {6, 7, 2} | {6, 7, 4} | {7, 2, 4} | {7, 2, 6} | {7, 4, 2} | {7, 4, 6} | {7, 6, 2} | {7, 6, 4} (total: 24)
