Question

Ratio of speed of boat in downstream and speed of stream is 9:1, if speed of current is 3 km per hr, then find distance travelled(in km) upstream in 5 hours.

Answer 1

hey
mate

here
is

your
answer


you are asking wrong question
$2x5x$

Answer 2

Hey dear,

◆ Answer-
s = 3.75 km

◆ Explaination-
Let vb be speed of the boat and vc be speed of water current.

Speed of the boat downstream-
vd = vb + vc

Speed of the boat upstream -
vu = vb - vc

Taking ratio,
vd / vu = (vb+vc) / (vb-vc)
9 = (vb+3) / (vb-3)
9vb - 27 = vb + 3
8vb = 30
vb = 15/4 km/hr

Substitutimg this value ,
vu = 15/4 - 3
vu = 3/4 km/hr

Distance travelled in 5 hours upstream is-
s = vu × t
s = 3/4 × 5
s = 3.75 km

Therefore, boat will travel 3.75 km in 5 hours upstream.

Hope it helps...