Estudian (present)
Estudiaron (past)
Well First of all Tener que means Must
so the list will be maybe like this If I understood the Question correctly
<span>Tener que tener pastel para la fiesta = must have cake for the party
Tener que </span><span>haber adivinar para la fiesta con regalos= must have guess with gifts
</span>Tener que <span>tener favores de partido = Must have party favors
hopefully I understood the question correctly and I was a help to you </span>
Do you want to translate this?
A cuantos estamos? means:
How many we are? or How many people are we in total?
Hope that helps!
Sorry I didn't see the question before