The 10/8 network has 16,777,216 addresses
The 172.16/12 network has 1,048,576 addresses
The 192.168/16 network has 65,536 addresses
Combine those with 65,536 port numbers for TCP and the same for UDP and you get over 2.3 trillion (2,345,052,143,616) potential service endpoints.
So next time someone wants you to scan their private IP space, doesnt tell you what ranges there are and expects you to do it in 2 weeks, tell them to politely fuck off.