Question

A motor boat whose speed is 18 km/ h in the still water takes 1 hour more to go 24 km upstream than to return downstream to the same spot. find the speed of the stream.​

Answer 1

Answer:

s= 6 km/ hr , speed of the stem cannot be negative

Answer 2

Let the speed of the stream be x km\hr.

The speed of the boat upstream = (18 - x) km/hr

The speed of the boat downstream = (18 + x) km/hr

Distance = 24 km

As given in the question,

Time for upstream = 1 + Time for downstream

24/(18 - x) = 1 + 24/(18 + x)

24/(18 - x) - 24/(18 + x) = 1

x2 + 48x - 324 = 0

(x + 54)(x - 6) = 0

x ≠ - 54 as speed cannot be negative.

x = 6

The speed of the stream = 6 km/hr