Q.

The number of 9 digit numbers, that can be formed using all the digits of the number 123412341 so that the even digits occupy only even places, is __________ .    [2023]


Ans.

(60)

Even numbers are 2, 4, 2, 4 

Odd numbers are  1, 3, 1, 3, 1

O¯E¯O¯E¯O¯E¯O¯ E¯O¯

Even places can be filled with even numbers in 4!2!2! ways.

Similarly, odd places can be filled in 5!2!3! ways.

Required number of ways =4!2!2!×5!2!3!=60