10
6
Six combinations: 123, 132, 213, 231, 312, 321
Not repeating, it is 7*6*5*4 which is 840 ways ---- There are 7 choices for each of four digits, right? 74 = 2401
120 combinations using each digit once per combination. There are 625 combinations if you can repeat the digits.
How many license plates can be made using either two uppercase English letters followed by four digits or two digits followed by four uppercase English letters?
45
6
To calculate the number of license plate combinations using three letters and four numbers, we consider the possibilities for each part separately. There are 26 letters in the English alphabet, so for three letters, there are (26^3) combinations. For the four numbers, using digits 0-9, there are (10^4) combinations. Therefore, the total number of combinations is (26^3 \times 10^4), which equals 17,576,000 combinations.
32C3 = 4960
Six combinations: 123, 132, 213, 231, 312, 321
Assuming you are treating each number as a number and not as an individual unit, the numbers you can make from these digits are 899, 989 and 998.
Not repeating, it is 7*6*5*4 which is 840 ways ---- There are 7 choices for each of four digits, right? 74 = 2401
94
3 x 3 x 3 x 3 = 81 combinations
I assume you mean how many 4-digit numbers can be made from a set such as {A,A, B, C} where A, B and C are single digits. There are 12 such numbers.
120 combinations using each digit once per combination. There are 625 combinations if you can repeat the digits.
017, 071, 107, 170, 701, 710. 6 combinations