"¿Cuántas bolsas tenemos?"
Translation:How many bags do we have?
"How many bags do we've" 6/4/18 reported I have never conjugated we-have at the end of a sentence, in terms of possession. I'm Almost certain its an error, but either way it is Unnatural in American English
Duo's database includes some contractions automatically, but it's not sophisticated enough to know when their use is incorrect- like at the end of a sentence.