This is the 1284th most frequent Catalan word.
quant
"Quant" in Catalan means "how much" or "how many."
Here, 'quant' is used as an interrogative adverb to inquire about the quantity of 'temps' (time).
Quant temps tens?
How much time do you have?
In this context, 'quant' functions as an interrogative adjective describing 'plàtan' (bananas).
Quant plàtan vol menjar?
How many bananas does he/she want to eat?
'Quant' here is used as a subordinating conjunction to denote the amount of the unknown cost.