英数题练习(附答案)3页.doc

冲南外英数题练习1. With the same engine power, if a ferry is running for 60km with the current, it takes 5 hours fewer than when it returns. When the engine power is doubled, that means the speed of ferry in still water is doubled, it takes 1 hour fewer when the ferry is running for 60 km with the current than it is against the current. Find the speed of the current in km/h.2. In ABC, lines are drawn from vertices A, B and C