Thread: Permutations without Repetition

How many different numbers can be formed by taking one, two, three, and four digits from the digits 1, 2, 7, 8, if repetition are not allowed ?

Please Help

I just tried this again, and i got the answer 64, am I correct ???

Originally Posted by creatively12

How many different numbers can be formed by taking one, two, three, and four digits from the digits 1, 2, 7, 8, if repetition are not allowed ?

Using the notation
the answer is .

Thanks for the reply

so my answer is correct right ???