Hey I got problems with a question...

"Suppose you have a request of 500, 2000, 4000 and 16000 addresses. For each of these, give the first IP adress assigned, the last IP address assigned and the mask in the (w.x.y.z/s) notation. The IP addresses are starting at 100.1.0.0"

Im clueless of what to do...

I've started like this thought:

2^x >= 500 => x = 9 => 2^9=512
2^x >= 2000 => x = 11 => 2^11=2048
2^x >= 4000 => x = 12 => 2^12=4096
2^x >= 16000 => x = 14 => 2^14=16384


I've tried to use this link: http://stackoverflow.com/questions/27011515/cidr-ip-assignment
To get some information but i'm struggling.

It seems as though the link you provided offers all of the help you would need for this, assuming you understand basic bitmath.