Rule for "number"

[guest]

I want to clarify the rules for the use of "number".

Which one is correct

Los Angeles has a higher number of family dwellings or
Los Angeles has higher numbers of family dwellings or both.

If both are correct usage when should we use "a higher number" and when "higher numbers"

[StaceyKoprince]

Generally you'd use only the first one. Do remember that if you are going to use "higher," then you're making a comparison, so you need to compare to something! For example:

Los Angeles has a higher number of family dwellings than it used to.

Los Angeles has a higher number of family dwellings than does any other city in the US.

There are some circumstances in the English language in which you could use "numbers" instead of "number," but the GMAT tends to stick to the singular here.