If 6 is placed at the right end of AB, so the number is AB6.
the value of the three-digit number formed is 294 more than AB, means that if AB6 - 294 = AB
AB 6
- 2 9 4
AB
6 - 4 = B = 2
If B = 2, then the tens digit is 2 - 9 (which can't be) so 12 - 9 = 3 = A
A = 3, and B = 2
check: 326 - 294 = 32