Question

How many number can be formed using all the digits 1234321such that even digits always occupy even places

Answer 1

Answer :-

18 numbers can be formed.

Step-by-step explanation :-

In the given 7 digits, we observe two 1's and two 2's and one 4.

The 3 even places can be occupied by the even digits 2,4,2 in 3!/2!

OEOEOE (Even places is shown by E)

The remaining 4 odd places can be occupied by the odd digits 1,3,3,1 in 4!/2!2! ways.

The number of required arrangements = 3!/2! × 4!/2!2! = 3 × 6 = 18