The answer is 6655.

**
This section requires Javascript.
**

You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.

dividing XXYY by 11 gives X0Y therefore X+Y=11 given X-Y=1 solving the two equations we get x=6 , y=5