ADA dua buah rumah. #buah" is fruit, but in this sentence it is used to describe the measurement. It just like saying "there are two PIECES of books". #pieces is the measurement of the books, like "buah" on the "rumah"

Two of you is "kalian berdua", if you want to say "three of you", you can say "kalian bertiga". Can you guess how to say "5 of you"??? Yes, you can say "kalian berLIMA" However, when you say, "two of them" the translation would be ambigious. When you say "MEREKA berDUA" it means that only 2 persons (from 2 persons), and when you translate it as "dua diantara mereka" it means that "two persons AMONG more than 2 person". Do you understand???? "Mereka berdua" and "dua diantara mereka" have the same translation in English. But slightly different meaning. LIke i've wrote previosly. We also distinguish "Kami" and "kita". Both of them are "we" in english, but different meaning. Kami = me and my friends, (youas my speaking paetner are not included) #kita = you, me, and my friend/your friends all are included