Combination lock on a suitcase has 5 wheels, each labeled with digits 1 to 8. ? - how many possible combinations are there on a 5 digit lock
5 How a combination lock code two digits are possible if no digit can repeat?
Tuesday, February 2, 2010
How Many Possible Combinations Are There On A 5 Digit Lock Combination Lock On A Suitcase Has 5 Wheels, Each Labeled With Digits 1 To 8. ?
5 comments:
Point is correct.
Here is the logic of the answer.
There are eight possibilities for the first place.
No matter what the first digit there are only seven possibilities for the second figure, because you can not use the same numbers again.
For the third digit 6 are possible, since you use 2 digits and can not be repeated.
For the fourth are 5 possibilities.
For the fifth there are 4 possibilities.
Therefore, you can:
8 x 7 x 6 x 5 x 4 possibilities
or opportunities 6720th
It is the same:
8 '/ (8-5)! = 8! / 3! = 6720
The formula is:
Na number of things, once elected, will not be repeated:
Number of things = N
N! / (N - n)!
The first digit can be selected in 8 species.
The second point can be selected in 7 species.
The third digit can be selected in 6 ways.
The fourth digit can be chosen in 5 ways.
The fifth point can be selected in 4 different ways.
Consequently, no. Alliance barrier = 8 * 7 * 6 * 5 * 4 = 6720.
Or, you know, you have 8 numbers on each wheel, and no numbers can be repeated. You need a 5-digit code. College does not count as 12345 is not the same as 21,345. However, nPr, where n is the total number of objects and R is the number of selected items. nPr is the name for a permutation. nPr = n! / (N - r)!
Therefore, there are 8-digits, and I want a 5-digit number.
Consequently, no. Alliance can 8P5 = lock = 8 '/ (8-5)! = 8! / 3! = 6720th
I hope that helps. :)
me07.
PS Make sure things before the NPR formula:
Repeats not allowed an object or a finger (can only be chosen once).
Orders must be imported (123 is not the same as 213 in a permutation, but if it was a partnershipmbination means 123, the same as 213).
r objects, one at a time, must be chosen from n objects.
8 '/ (8-8!)
= 40320 combinations
8 '/ (8-8!)
= 40320 combinations
8 * 7 * 6 * 5 * 4 = 6720
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