Question

How many 9 digit palindromes are there with all the digits being even and each digit appearing no more than once

Answer 1

Answer:

96

Step-by-step explanation:

We have to find number of 9 digit palindromes  when all digits are even and each digit appearing not more than twice.

Digits used here

0,1,2,3,4,5,6,7,8,9

Total number of even digits=0,2,4,6,8=5

Now,

0 cannot be used for first place if number is 9-digit number.

Firs place can be filled by number of ways=4

Second place can be filled by number of ways=4

Third place can be filled by number of ways=3

Fourth place can be filled by number of ways=2

Fifth place can be filled by number of ways=1

Total number of ways=$4\times 4\times 3\times 2\times 1$

Total number of ways=96

Hence, total number of 9-digits palindromes  when all digits are even and appearing not more than twice=96