You have 4 options for the first digit, 3 for the second, 2 for the third. Multiplying all this you get 4 x 3 x 2 = 24 options.
From left to right, pick the smallest possible digit every time. This will give you the smallest possible number.
Number of 7 digit combinations out of the 10 one-digit numbers = 120.
20From Rafaelrz,The number of three digit permutations you can get from the four different digits3. 6. 7. 9, is given by:4P3 = 4!/(4-3)! = 4x3x2x1/1 = 24
4,748,472 Confirmed using the following C# function string sTemp; int total = 0; for (int i = 1000000; i < 10000000; i++) { sTemp = i.ToString(); if (sTemp.Contains("7")) { total++; } } label1.Text = total.ToString();
It is difficult to interpret exactly what you are trying to ask. If you allow your five digit number to have leading zeroes and do not allow negative numbers, then 00000 - 99999 = -99999 is the smallest number. If you do allow negative 5 digit numbers, then (-99999) - 99999 = -199998 is the smallest number.
3! = 6.
From left to right, pick the smallest possible digit every time. This will give you the smallest possible number.
Number of 7 digit combinations out of the 10 one-digit numbers = 120.
210
There are 2 choices for every digit in the 6-digit number. So 26 is 2*2*2*2*2*2. The answer to that is 64.
There are 5 numbers which can make the 3 digit numbers in this example. Therefore each digit in the 3 digit number has 5 choices of which number can be placed there. Therefore number of 3 digit numbers = 5 x 5 x 5 = 125
To create a numeric palindrome using two-digit numbers, take a two-digit number, such as 23, and reverse its digits to form 32. Then, combine the two numbers to create a three-digit palindrome by placing the first number before the reversed second number, resulting in 232. Thus, any two-digit number can generate a three-digit palindrome by following this method.
24680
625×2=1250
88,888
1,023.
123478