Rate of the boat in still water:81 km/h
Rate of the current: 18km/h
What is speed?
Speed tells us how fast something or someone is travelling. You can find the average speed of an object if you know the distance travelled and the time it took. The formula for speed is speed = distance ÷ time.
Given
b= speed of boat in still water c=speed of current
"boat travels 693 kilometers in 7 hours going downstream" Going downstream, the boat travels b+c km per hour. b+c km/hr = 693 km/7hr = 99 km/hr
b+c=99
"boat travels 189 kilometers in 3 hours going upstream" Going upstream, the boat travels b-c km per hour. b-c km/hr = 189 km/3hr = 63 km/hrb-c=63
Add the equations together to eliminate the c terms: b+c=99 b-c=63 2b = 162, therefore, b= 81
b+c= 99, so c = 99 - b= 18
To know more about speed refer to :
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