Self Check Answers

1. 4
2. No. Since 71 contributes 2 to the last digit of the weighted sum of the digits of $71a_3{a}_4\cdots a_8$ and 17 contributes 8 to the last digit of weighted sum of the digits of $17a_3{a}_4\cdots a_8,a_9$ is not the last digit of the weighted sum of the digits $17a_2{a}_3\cdots a_8$.
3. 29
4. 1
5. 5
6. J255