How many numbers are there in between 1245 and 5421 which contain each of digits 1,2,4,5?
Answers
Answered by
2
We have to make a 4 -digit number with 1,2 ,4 and 5.
There are 4! such numbers.
But since we cannot include 1245 and 5421, there are 4! -2 required numbers
=4!-2
=24-2=22
Don't worry about the numbers being smaller than the required numbers, as 1245 is the least possible number with these digits and 5421 is the maximum.
There are 4! such numbers.
But since we cannot include 1245 and 5421, there are 4! -2 required numbers
=4!-2
=24-2=22
Don't worry about the numbers being smaller than the required numbers, as 1245 is the least possible number with these digits and 5421 is the maximum.
Answered by
1
Answer :
There 24 ways to write 1,2,4,5 or 4!
1,2,4,5 is taken
starting with 1, only 5
starting with 2, 6 ways
starting with 4, 6 ways
starting with 5, 5,4,2,1 is taken and the rest is lower than 5421
Similar questions