Check grammar: Please check grammatical error of the following sentences with explaination. Thanks.?

Having countless no. of guest rooms=adj clause to word"hotel"=a pair of twins X countless no. of rooms=No. of twins staying .

Imagine that a jumbo-sized hotel (possesses) (countless guest rooms) is (booked out) and each room is occupied by at least a pair of twins, (then) how many twins are staying in this hotel?

說明：countless 直接後接名詞即可。基本上沒什麼錯誤，我只是稍加修飾，例如：having 是正確的，"is full" 我改為"be booked out""客滿"，我認為如此文意上更明確，在"how many"前加then"那麼", 讓文意的轉折更順一些。

試想像: 一個超級大型旅店 有著無數的 客房 而且客滿地 每個客房都住著 至少一對雙胞胎客人.
醬子的話 這旅店 住有幾位雙胞胎呢?

grammar wise, it is certainly correct.

By our imagination that a six-storeyed built hotel with lots of guest-rooms is full and each room is occupied by at least a pair of twins. How many twins are staying in this hotel? Yip