It means: 'And how many?'
Cuantas means How many.
"Cuantas" in English translates to "how many" or "how much" depending on the context.
how many people are there in your family?
It means how many windows are there in the house?
how many letters does the English alphabet have
cuantas millas hay entre miami y kansas
This could be a statement by a PETA member. It means, "How many lives for an overcoat?" It could also mean, "So many lives for an overcoat!"
I pretty sure it means, "there are many classes each week"
It means "How much."
how much
Il y a means "there is / there are" in English.
That is Spanish for "How many rooms does it have?"