The right answer is "2"
the divisiveness rule says that the number which it's last two digit is divisible to 4 and 2 is divisible to 8 so if you add another digit you have to make it divisible to 4 and 2 which in this case is number "2"
I solved and the mean is 10
If you work out the equation the answer would be 5 but its not a definite answer.
