The speed of a boat in still water is $9$ km/hr. If the boat goes $54$ km downstream in $4$ hours, find the speed of the stream.

2.5

km/hr

No worries! We‘ve got your back. Try BYJU‘S free classes today!

4.5

km/hr

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

3.7

km/hr

No worries! We‘ve got your back. Try BYJU‘S free classes today!

5.7

km/hr

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B $4.5$ km/hr
Speed of boat $= 9$ km/hr
Speed of stream $= x$ km/hr
Speed of boat downstream $=$ speed of boat $+$ Speed of stream
$= (9 + x)$ km/hr
Distance covered by boat in $4$ hrs upstream $= 54$ km
Speed of boat upstream $(9 + x) = \frac{54}{4} = 13 \frac{1}{2}$
$x = 13 \frac{1}{2} - 9$ km/hr $= 4.5$ km/hr

Suggest Corrections

Similar questions

A boat covers 32 km upstream and 36 km downstream in 7 hours. Also, it covers 40 km upstream and 48 km downstream in 9 hours. Find the speed of the boat in still water and that of the stream.

Q. In one hour, a boat goes 11 km/hr along the stream and 5 km/hr against the stream. The speed of the boat in still water (in km/hr) is:

A boat travels at 8 km/hr in still water and water flows at 4 km/hr. The speed of the boat if it goes against the water stream is?

A motorboat travels 30 km downstream in 3 hours and 40 km upstream in 5 hours. Find the speed of the boat (in km/hr).

Q. A boat whose speed in

15 k m / h r

in still water goes

30

km downstream and comes back in a total of

4

hours

30

minutes. the speed of the stream (in km/hr) is :

Join BYJU'S Learning Program

The speed of a boat in still water is 9 km/hr. If the boat goes 54 km downstream in 4 hours, find the speed of the stream.

The correct option is B 4.5 km/hrSpeed of boat =9 km/hrSpeed of stream =x km/hrSpeed of boat downstream = speed of boat + Speed of stream=(9+x) km/hrDistance covered by boat in 4 hrs upstream =54 kmSpeed of boat upstream (9+x)=544=1312x=1312−9 km/hr=4.5 km/hr

The speed of a boat in still water is $9$ km/hr. If the boat goes $54$ km downstream in $4$ hours, find the speed of the stream.