Hamming code exercise
How I did it was: Use the original data word and fill in the new check bits. : 

001111001101

Then again get the positions where the 1s are and convert that number to binary:

1 : 0 0 0 1

3 : 0 0 1 1

4 : 0 1 0 0

7 : 0 1 1 1

8 : 1 0 0 0

9 : 1 0 0 1

10: 1 0 1 0



1 0 1 0


So this means that the 10th bit is wrong

Since I don't have the actual  solution, i do not know if this is correct, bit it fits the way I learned how to do this.