Question

求解一道数学题目.....

求解 !!!!A speedboat takes 1 hour longer to go up a river than to return. If the boat cruises at 10 miles per hour in still water,what is the rate of the current?求解 !!!!

Answer 1

假设去时用了1小时,河流的流速度为S,那么根据题目回来时用了两个小时,则:
10+S=2*(10-S),求得S=10/3
假设用了去时N个小时,那么根据题目回来时用了N+1个小时,则:
N(10+S)=(N+1)(10-S),求得S=10/2N+1,如果用的时间越长,流速越慢,望采纳

Answer 2

If the boat cruises at 10 miles per hour in still water
是不是如果船以10的速度那么就一直在水里啊，所以水速就是10啊