The preterite tense is one of two simple past tenses. It is used to describe actions that took place or were completed at a certain point in the past. From these sentences, we have the following subject pronouns:
Nosotros that means we
Tú that means you
Yo that means I
So the correct answers are:
Nosotros salimos del hotel.
Nosotros abrimos el libro
Tú subiste las maletas.
Yo subí por la escalera.
Tú recibiste una tarjeta postal.
All these verbs are regular. If you want to conjugate a regular verb in the preterite tense, you must remove the infinitive ending (ar, er, or ir) and add the preterite ending that matches the subject. Check out the Table below of regular preterite endings.