how many 4 digits cvombos can you make with only 8 numbers

Question

with only 8 random number how many differant combos can be tryed total?

Answer 1

If we start with 8 different numbers, we have a choice of eight in our first selection.

For our second choice we have a choice of seven, then six, and finally five.

So that's 8×7×6×5. But we can have any order and for four different numbers there are 4!=24 different arrangements.

So the total number of combinations (irrespective of order) is 8×7×6×5/24=70 different combinations.