10:10
Well, I assumed it was more of a math/geometry/topology problem.
i.e. If there are bendy streets, maybe it's impossible to lay out a pattern that has lots the same size without some of the streets being dead-ends.
10:14
Wait a minute. "For x houses". All the bendy streets will have more houses on one side than the other (unless they curve twice, cancelling out). Cul-de-sacs make up the difference, since they provide more hourse per unit of street than a regular house does.
I think I'm on the right track, but I don't have it yet.
10:17
No, it can't be right, it still would have had to stipulate some constraint on the lot sizes/shapes, wouldn't it?
10:18
Unless can be just assumed that, in a new housing development, all lots are designed to have the same area (if not the same shape).
10:19
Nope, still doesn't work. You can always make the lots the same area if you don't have to worry about the shape. You can make em longer and narrower.
10:20
Oh wait. Tribdog already provided the answer.
Um. Nevermind.