Question

please refer to the image and solve no.17 I have got the ans speed of boat =6km/h and speed of stream =2km/h but I doubt there are more than one value for speeds of stream and boat since it is in two variables.​

Answer 1

Answer:

Step-by-step explanation:

Let speed of the boat be x km/h and speed of stream be y km/h

Now, speed in downstream = x + y km/h

Time = 2hr, Distance = 20 km

Distance = speed × time

2(x + y) = 20

x + y = 10 .........eq 1

Speed in upstream = x - y km/h

Time = 4hr , Distance = 4 km

Distance = speed × time

2(x-y) = 4

x-y = 2 ........eq 2

Adding eq 1 and eq 2

2x = 12

x= 6km/h

putting value of x in eq 1

6+y=10

y = 4 km/h

So, Speed of boat in still water = 6km/h

Speed of stream =4km/h