Premise: "Two old people look on at a guy selling something for 1.20 euro."
Hypothesis: "Two old people are waiting to see if the sale happens because they want to buy the item."
Do we know that the hypothesis entailed by the premise? Stream of thoughts:
Two old people look on at a guy selling something for 1.20 euro. does not indicate that they are waiting to see if the sale happens because they want to buy the item.
Therefore, the answer is it is not possible to tell.