not a video, but Paul Browning's system helped me a lot: Zero to Guru
That's two questions in one really. One is finding the subnet the host is in and the other is the design type with how many subnets/hosts.
Well the quick way is to work out that the subnets go up in increments of 16 on the third octet. You can work it out as in binary 240 is 11110000. I made a video a while ago showing you how to write a subnetting cheat chart you can use in exams.
I wrote a book on Subnetting the easy way if you want to check it out:
https://www.amazon.com/IP-Subnetting-Zero-Paul-Browning-ebook/dp/B07KV7N8WS
Regards
Paul
the best resource is the one which makes sense to you. I wrote the best selling Subnetting book (according to Amazon):
https://www.amazon.com/IP-Subnetting-Zero-Paul-Browning-ebook/dp/B07KV7N8WS
Otherwise, there is a video with all you need to know on YT:
Let me know how you get on.
regards
Paul
I put this on YouTube recently - https://youtu.be/UcV1JaT0FZc
I wrote this also - https://www.amazon.com/IP-Subnetting-Zero-Paul-Browning-ebook/dp/B07KV7N8WS
Regards
Paul
This is what really helped me: https://www.amazon.com/IP-Subnetting-Zero-Paul-Browning-ebook/dp/B07KV7N8WS