Answer: rate of tug of the river = 7 miles per hour
rate of the boat = 17 miles per hour
Step-by-step explanation:
Let the speed of the boat be x miles per hour
Let the speed of the tug of the river be y miles per hour
Speed = distance / time
If a boat goes downstream 72 miles in 3 hours, the the speed is
72/ 3 = 24 miles per hour
Since the speed is higher than when it went upstream, it means that it moved in the same direction with the wind hence, it moved in still water.
The total speed would be x -y. Therefore
x + y = 24 - - - - - - -1
If a boat goes downstream 60 miles in 6 hours, the the speed is
60/ 6 = 10 miles per hour
Since the speed is lower than when it went downstream, it means that it moved in the opposite direction of the tug of the river.
The total speed would be x -y. Therefore
x - y = 10 - - - - - -2
Adding equation 1 and equation 2
2x = 34
x = 34/2 =17
y = 24 - x = 24 - 17
y = 7
