How many 3 digit numbers contain the digit 3 at least once?
To find the number of 3-digit numbers that contain the digit 3 at least once, we can use the concept of complementary counting. There are a total of 900 three-digit numbers (ranging from 100 to 999). To find the numbers that do not contain the digit 3, we calculate the numbers with digits 0, 1, 2, 4, 5, 6, 7, 8, and 9 in each place. There are 8 choices for each place, so the total number of three-digit numbers without the digit 3 is 8 x 9 x 9 = 648. Therefore, the number of three-digit numbers that contain the digit 3 at least once is 900 - 648 = 252.