I have a solution which you might like to look at.
I do not have time to post it in detail here. However it is documented in the LTspice files in the archive:
that I have uploaded and publicly shared here
You'll need to install:
LTspice runs natively on Windows and, using WINE, on Linux and Mac.
Unzip the .asc and .plt files from the .7z into the same folder.
Open the .asc file in LTspice.
BTW: There are two LTspice sims in the archive. One is the detailed solution, the other is a sanity check.
If you can't open .7z archives, Google for 7zip and install that.
You can also find a bit more about solution if you follow the link to your original enquiry on Circuitlab:
If anyone wants to, they are welcome to work through the solution and post an explanation here, rather than have to follow a few links that may or may not survive much beyond the end of eggie5's assignment.
As far as I can see from the Terms of Service page on the CircuitLab site, there are no restrictions on the copying or other forms of reuse of content posted on their site, provided that the original content does not in itself violate copyright laws.
To my knowledge, the content I have posted there does not violate copyright.