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=[tex]4\times 4\times 3\times 2\times 1[/tex]
Total number of ways=96
Hence, total number of 9-digits palindromes when all digits are even and appearing not more than twice=96
