Question

A boat travels upstream from q to p and downstream from p to q in 3 hours. if the speed of the boat in still water is 9 km/hr and the speed of the current is 3 km/hr, the distance between p and q is :

Answer 1

Speed of downstream = (9+3) km/hr = 12 km/hr
Speed of upstream = (9-3)km/hr = 6 km/hr
Let the distance AB = x km
Then, x6+x12=3⇒x6+x12=3⇒
2x + x = 36 \Rightarrow x = 12$
Distance AB = 12 km.

Answer 2

Dear Student,

◆ Answer -

Distance between P and Q = 12 km

● Explanation -

Speed upstream is -

vu = vb - vr

vu = 9 - 3

vu = 6 km/hr

Speed downstream is -

vd = vb + vr

vd = 9 + 3

vd = 12 km/hr

Let s be distance between P and Q.

t = s/vu + s/vd

3 = s/6 + s/12

3 = s/4

s = 4 × 3

s = 12 km

Hence, distance between P and Q is 12 km.

Thanks dear. Hope this helps you...