The total number of three-digit numbers, with one digit repeated exactly two times, is ______.

Step-by-step solution

For three digit number we have following cases, Case I: When digit zero is repeated Number of numbers = C 1 9 = 9 Case II: When digit zero is present but not repeated Number of numbers = C 1 9 · 2 ! = 18 Case III: When digit zero is not present Number of numbers = 9 · 8 · 3 ! 2 ! = 216 Total number of numbers = 243