First, I have never used this model, but to answer all the questions, there are two slots and a 5th generation CPU and chipset. You should be able to use 2X16GB = 32GB of memory.
8GB + 4GB will work fine but you will not be able to use dual-channel access. In real life operation, dual-channel advantages are more theoretical than actual. You are unlikely to notice the difference.
Rich
I do not respond to requests for private, one-on-one help. Your questions should be posted in the appropriate forum where they may help others as well.
If a response answers your question, please mark it as the accepted solution.
I am not an employee or agent of Lenovo.
