This is an ambiguous question. Are you asking for the number of combinations, or to actually list them? Since we haven't been given the 8 numbers, I assume the former. Are you asking for the number of combinations of 4 different numbers selected from the given 8, or are duplicates allowed?
The latter is kind of complicated. The number of permutations of 4 numbers selected from 8 given numbers (or any 8 things) is very easy: since each of the 4 positions in the sequence can be any of the 8, you get 8 raised to the 4th power, which is 4096. But to get the number of combinations, you have to eliminate the duplications, and the number of duplications for a permutation depends on the number of repetitions within the permutation itself. For example, the permutation (1, 2, 1, 2) has 2 pairs; you need to count the number of combinations of the 4 positions where the 1s can go, and the other 2 positions would have 2s. That number turns out to be 6, but if there is only 1 pair, as in (1, 1, 2, 3) you have 6 pairs of positions to put the 1s in, and 2 ways of ordering the 2 and the 3, so you get 12. I could go on and on.
If you don't allow duplications, then you have 8 x 7 x 6 x 5 possible permutations, which is 1,680. Each of these can be ordered 4 x 3 x 2 x 1 ways, which is 24. Dividing 1,680 by 24 gives 70 combinations
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To calculate the number of combinations of 4 numbers from 8 numbers, you would use the combination formula, which is nCr = n! / (r!(n-r)!). In this case, n = 8 and r = 4. Plugging these values into the formula, you get 8C4 = 8! / (4!(8-4)!) = 70. Therefore, there are 70 possible combinations of 4 numbers that can be chosen from a set of 8 numbers.
To calculate the number of combinations for the numbers 1248, we need to consider all possible arrangements of the four digits. Since all the digits are unique, there are 4 factorial (4!) ways to arrange them. This equals 4 x 3 x 2 x 1 = 24 combinations.
The answer is 10!/[6!*(10-6)!] where n! represents 1*2*3*...*n Number of combinations = 10*9*8*7*6*5*4*3*2*1/(6*5*4*3*2*1*4*3*2*1) = 10*9*8*7/(4*3*2*1) = 210
Oh honey, let me break it down for you. With the numbers 0 and 8 repeated twice, you're looking at a total of 4!/(2!2!) = 6 combinations. So, you've got 0088, 0808, 0880, 8008, 8080, and 8800. That's all she wrote, darling.
Two . . . . . 38 and 83.