how to tackle this route summarization qs?

[Hondabuff]

Could you use your method on

10.1.2.0
10.1.7.0
10.1.9.0

10.1.{0-8 not enough because of the 9, 0-16 will cover all of  0-2-9-16} .0 All routes from 1-15 will be included because of the overage.
Technically it would be considered a poorly designed network.

0-8, 0-16, 0-32, looks like all we need is 16 places to cover them all. We will be wasting places because the 10.1.9.0 is in the next block of 8.
So a summarized network of 10.1.0.0/20. A block size of 16 is a 240 mask.
The 10.1 make up 16 bits allready and 240 mask uses 4 bits. 16+4=/20