This question already has an answer here:
There is a recorded announcement I hear several times a day on the trains I catch to and from work. Here is part of the announcement:
This train contains quiet carriages. Both the first and the last carriages are quiet carriages.
To me, this always sounds wrong. It feels like it should be
This train contains quiet carriages. Both the first and the last carriage are quiet carriages.
This feels more apt, since each of the carriages being mentioned are singular. You would say for instance
First and second place both get a medal
rather than places. Once you go to three or more things, then it is pluralised
The first three places get medals.
Is this all correct? It's been bugging me for a while.