Question 843940: digits:1,2,3,4,5,6,7,8,9 No repetition is allowed
a)how many 5 digit numbers are there that exclude 0 and 7
b) How many of them start with an even number
c) how many of them start and end with and even number
Found 2 solutions by Edwin McCravy, AnlytcPhil:
Answer by Edwin McCravy(20056)   (Show Source):
You can put this solution on YOUR website! digits:1,2,3,4,5,6,7,8,9 No repetition is allowed
a)how many 5 digit numbers are there that exclude 0 and 7To exclude 0 and 7 we can only choose
from the 8 {1,2,3,4,5,6,8,9}
We can choose the 1st digit 8 ways.
We can choose the 2nd digit 7 ways.
We can choose the 3rd digit 6 ways.
We can choose the 4th digit 5 ways.
We can choose the 5th digit 4 ways.
8*7*6*5*4 = 6720b) How many of them start with an even numberWe can choose the 1st digit 4 ways.
We can choose the 2nd digit 7 ways.
We can choose the 3rd digit 6 ways.
We can choose the 4th digit 5 ways.
We can choose the 5th digit 4 ways.
4*7*6*5*4 = 3360 c) how many of them start and end with and even number.We can choose the 1st digit 4 ways.
We can choose the 5th digit 3 ways.
We can choose the 2nd digit 6 ways.
We can choose the 3rd digit 5 ways.
We can choose the 4th digit 4 ways.
4*3*6*5*4 = 1440
Edwin
Answer by AnlytcPhil(1806)  (Show Source):
You can put this solution on YOUR website! digits:1,2,3,4,5,6,7,8,9 No repetition is allowed
a)how many 5 digit numbers are there that exclude 0 and 7To exclude 0 and 7 we can only choose
from the 8 {1,2,3,4,5,6,8,9}
We can choose the 1st digit 8 ways.
We can choose the 2nd digit 7 ways.
We can choose the 3rd digit 6 ways.
We can choose the 4th digit 5 ways.
We can choose the 5th digit 4 ways.
8*7*6*5*4 = 6720b) How many of them start with an even numberWe can choose the 1st digit 4 ways.
We can choose the 2nd digit 7 ways.
We can choose the 3rd digit 6 ways.
We can choose the 4th digit 5 ways.
We can choose the 5th digit 4 ways.
4*7*6*5*4 = 3360 c) how many of them start and end with and even number.We can choose the 1st digit 4 ways.
We can choose the 5th digit 3 ways.
We can choose the 2nd digit 6 ways.
We can choose the 3rd digit 5 ways.
We can choose the 4th digit 4 ways.
4*3*6*5*4 = 1440
Edwin
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