Question 713150: I've submitted this twice, can someone please help. I've completed the first 4 questions, these two are impossible to understand. Bless your heart for the help.
Use the digits 0 through 9, how many 4 digit numbers can be formed:
A) If the number must be between 5001 and 8000, digits may not be repeated.
B) The number must begin and end with an odd digit, digits may not repeat.
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! Use the digits 0 through 9, how many 4 digit numbers can be formed:
A) If the number must be between 5001 and 8000, digits may not be repeated.
--------------
The 1st digit is 5, 6, or 7 -->
The 2nd digit is 1 of 9
The 3rd is 1 of 8
The 4th is 1 of 7
--> 3*9*8*7 = 1512
------------------
B) The number must begin and end with an odd digit, digits may not repeat.
1st digit is 1 or 5, last is 1 of 4
The 2nd is 1 of 8
The 3rd is 1 of 7
--> 5*4*8*7 = 1120
|
|
|
