"The majority are seventy years old."
Translation:Majoritatea au șaptezeci de ani.
Here, I am not claiming a violation of proper English. I am claiming that the Romanian ending of "majoritatea" is clearly a singular + definite article noun and the verb "a avea" should agree with it. So it should be "Majoritatea are saptezeci ani." I noticed somewhere else in the same module "majoritatea" does have a singular, third person verb used with it. I am not trying to be the Grammar Police here. I'm just trying to be helpful.
Sorry, I misread your comment. The thing is that "majoritatea" behaves the same as in English, so it can be followed by a verb conjugated either in singular or plural, depending on whether you want to emphasis the individuals or the group. This article in Romanian explains it better (second paragraph).
Thanks for the very interesting article and website dexonline.ro! You are right, it does appear "majoritatea" can use a plural verb form just like in English. The article makes the distinction between a "compact group" ("The parliamentary majority opposes the law") and a "number within a group" ("A majority of the boys are bad").