@sreshta - it is my humble request to you, to please not compare unrelated questions and attempt to learn concepts by cross-referencing. It is a very dangerous thing to do - and other readers will also pick up wrong concepts.
That question that you have linked - it is related to CIDR. It is clearly given that the network mask is 27 bits, they're asking you to find the last host. They are NOT asking you to figure out last-subnet/first-subnet, etc. They are saying very clearly first 27 bits are already set for NID, with the remaining 5 bits - what is the last host.