Please post an answer related to my question and not any random answer, if you don't know the answer don't answer please, because this happened a lot.

Sara has promised her parents that she will visit them over the summer. The normal round-trip airfare is 2500, but the airline serving her parents' hometown is offering a reduced round-trip airfare of 1200. The reduced fare tickets must be purchased within the next five days and are nonrefundable. Travel dates may be changed at a cost of 150 if the airline has space available. Sara would really like to take advantage of the low airfare, but since summer is still four months away, she is concerned that she may not be able to get away from her job on the travel dates she selects. She estimates that there is a 30% chance that she will not encounter this difficulty. If she has to change her travel dates, Sara estimates there is a 50% chance that the airline will have space available. If space is not available, Sara will have to buy an additional full-fare ticket. Another option is for Sara to wait two months to buy the tickets. By that time she will know exactly when she can take summer vacation. Sara estimates that there is a 60% chance that the airline will offer a reduced fare of 1350 at that time and a 40% chance that the fare will be 2500. Use a decision tree to represent this problem and determine whether Sara should purchase the 1200 discount ticket or no