Are the sentence correct grammatically?

[kelvin123]

1 The homeless need our help.
2 Homeless need our help. (the word "people" is omitted)
3 Homeless people need our help.

1 The elderly need our support
2 Elderly need our support. (the word "people" is omitted)
3 Ederly people need our support.

Are the sentence have the same meaning and correct grammatically?
thanks

 

[Barb_D]

The second one in each set doesn't work, but 1 and 3 mean the same thing.

 

[kelvin123]

but can't the word "people" be omitted?

 

[Barb_D]

but can't the word "people" be omitted?

If you do, then you need the "the" as you do in the 1s.