Answer:
Rate in still water = 45 km/h
Rate of the current = 10 km/h.
Step-by-step explanation:
Let the rate of the current be x and rate in still water be y.
So the rate of the boat upstream is y - x and the rate downstream = x + y.
Rate upstream = distance / time
y - x = 105/3 = 35 ...... (1)
Rate downstream:
y + x = 165/3 = 55 .......(2)
Adding (1) + (2):
2y = 90
y = 45 km/h.
Using equation (1):
45 - x = 35
x = 45-35 = 10 km/h.
