Answer:
The crew rowing rate in still water = 7km/hr
The rate of the current = 4km/hr
Step-by-step explanation:
The distance rowed downstream with the current = 33km
Time taken to row downstream = 3hrs
The distance rowed upstream against the current = 33km
Time taken to row upstream = 11hrs
Let the crew's rowing rate in still water = Xkm/hr
Let the rate of current = Ykm/hr
For the downstream movement, we will have (X+Y). This is because the boat rowed with the current
For the upstream movement, we will have (X-Y). This is because the boat rowed against the current
Downstream Speed = distance /time
= 33/3
= 11km
Upstream speed = distance /time
= 33/11
= 3km
Hence X+Y = 11 and X-Y= 3
Add both equations. We have
X+Y+X-Y = 11 + 3
2X = 14
X= 14/2
X= 7
put X= 7 in any of the equations
7-Y= 3
Y= 7-3
Y= 4
Hence the crew rowing rate in still water = 7km/hr and the rate of the current = 4km/hr
