Question 388255: 1) Using the numbers ( 0,1,2,3,4,5,6), how many four digit numbers contain 2 as a digit can be written if repetition is not allowed?
2) Using the numbers (1,2,3,4,5,6), four digit numbers are written without repetition. In how many of these, are the digits 1 and 2 not adjacent?
3)Using the numbers (1,2,3,4,5), five digit numbers are written without repetition. In how many of these, digit 1 comes before 2?
Answer by edjones(8007)   (Show Source):
You can put this solution on YOUR website! 1) 2 can be in any one of 4 positions = 4
nPr=6P3=120 There are 6 other numbers that can be used in the 3 positions where number two isn't located.
120*4=480
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Ed
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