Question

a motorboat whose speed is 90 metre per hour in still water goes 15 km downstream and comes back in a total time of three hours 45 minutes find the speed of the stream​

Answer 1

Answer:

3 km/h

Step-by-step explanation:

Letspeedofstream=xkm/hr

then(

9+x

15

)+(

9−x

15

)=3+(

4

3

)hour

15(

81−x

2

9−x+9+x

)=(

4

15

)

72=81−x

2

∴x

2

=81−72

∴x=3km/hr