Question

.A boat takes 20 hours tp travel downstream from point p to point q and coming back to a point r midway between p and q .If the velocity of the stream is 5 kmph and the speed of the boat in still water is 13 kmph.Then what is the distance between p and q?

Answer 1

ni ata yr bhot try bhi kra

Answer 2

Hey dear,

◆ Answer-
PQ = 122.4 km

◆ Explanation-
# Given-
vb = 13 km/h
vs = 5 km/h
t = 20 h

# Solution-
Relative velocity of boat downstream -
vd = vs + vb
vd = 5 + 13
vd = 18 km/h

Relative velocity of boat against stream-
vu = vb - vs
vu = 13 - 5
vu = 8 km/h

Let s be the distance between P to Q, then
s/8 + 0.5s/13 = 20
(13s + 4s) / 104 = 20
17s = 2080
s = 122.4 km

Distance between P to Q is 122.4 km.

Hope this helps you...