How many different 4 digit numbers can be formed using the digits 1, 2, 5, 6, 7 and 8?

To solve this problem, we need to use the concept of permutations.

Step 1: Understand the problem We are asked to find out how many different 4-digit numbers can be formed using the digits 1, 2, 5, 6, 7, and 8.

Step 2: Identify the number of options for each digit We have 6 different digits and we need to choose 4 of them. For the first digit, we have 6 options (it can be any of the 6 digits). For the second digit, we have 5 options left (since we can't repeat a digit). For the third digit, we have 4 options left, and for the fourth digit, we have 3 options left.

Step 3: Calculate the total number of permutations The total number of permutations is the product of the number of options for each digit. So, we multiply 6 * 5 * 4 * 3 to get the total number of permutations.

Step 4: Solve 6 * 5 * 4 * 3 = 360

So, there are 360 different 4-digit numbers that can be formed using the digits 1, 2, 5, 6, 7, and 8.