It is not a full sentence but it means: there is a _____ on the wall.
"cuántos cuartos hay en la casa?" means "How many rooms are there in the house" in English.
The litteral translation is - There are students in the class Mexico
It means "What is there in the students desk?"
it means to Dream Big
Estas pendejo en la casa hay frijoles
I think it means what's in your school?
how many people are there in your family?
It means "What is there in the big cities?"
A good interpretation would be "What's in class?"
"How many days are there in a year?"
cuantos dias hay en una semana
It means: "How many days are there in this month?"