Một phòng họp có 180 người được xếp đều trên các dãy ghế. Nếu thêm 80 người thì phải kê thêm 2 dãy ghế và mỗi dãy ghế tăng thêm 3 người. Hỏi lúc đầu phòng họp đó có bao nhiêu dãy ghế ?

1. the wheeling bridge in west virginia is about 307 meters long. if you walk with a stride of about meter, about how many steps would it take you to cross this suspension bridge?

The krasnapolski is a top-of-the-line hotel in amsterdam, the netherlands. among their many services, they rent bicycles to guests. the bicycle checkout is open 24 hours per day 7 days per week and has 50 bicycles on hand. on average, 10 guests request a bicycle each day, arriving completely randomly at all times of the day during the spring and summer seasons. guests keep bicycles for four days on average, with a standard deviation of two days. how long does a guest on average have to wait for a bike? a. approximately 24 hours b. approximately 0.033 hours c. approximately 4 days d. approximately 47 minutes

The midpoints of the sides of the large square are joined to form a smaller square. what is the area of the smaller square