Neighbor houses
On the same side of a street will be built 6 neighboring houses. Houses may be made of brick or wood, but as a fire safety measure, two wood houses can not be neighbors. In how many ways can you plan to build these houses?
The answer is 21.
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.
0 solutions
No explanations have been posted yet. Check back later!