how does petruchio learn what drowry baptista plans to give any husband of kate?

Petruchio abruptly demands of Baptista what dowry he will receive when he marries Katharina, upon which Baptista replies: "After my death the one half of my lands,/And in possession twenty thousand crowns." (2.1: 121-122) Petruchio is satisfied, and reassures Baptista that he will successfully woo the feisty Katharina.