Question 327329
Think it through.  If the 100's digit is 3 times the tens digit, there are a few candidates we can have. 

Let the 10's digit be 3. Then, since the 100's digit is 3 times that, it must be 9. The 3 digits sum to 19, so the 1's digit must be 7.

So, we have 937. Reverse this and we have 739. Which is 198 less than 937.

Check.