Isn't

[Allen165]

Shouldn't the following sentence start with "aren't"?

Isn't three centers too many?

Thanks.

[RonBee]

Yes.

A: Aren't three centers too many?
B: Yes, three centers are too many.

[Nightmare85]

I believe you can use isn't if you also use much:
Isn't three centers too much?
Aren't three centers too many?

When you say too many, you automatically count something (-> plural), which is in our case three centers.

**Neither a teacher nor a native speaker.**

Cheers!