All possible numbers are formed using the digits 1, 1, 2, 2, 2, 2, 3, 4, 4 taken all at a time. The number of such numbers in which the odd digits occupy even places is

All possible numbers are formed using the digits 1, 1, 2, 2, 2, 2, 3, 4, 4 taken all at a time. The number of such numbers in which the odd digits occupy even places is

1 Answer

127 votes

There are total 9 digits; out of which only 3 digits are odd.

Number of ways to arrange odd digits first

= ^{4}C_{3} .

Total number of 9 digit numbers =^{.}

= 180

127 votes

127