Question

a moter boat whose speed is 24km/hr in still water takes 1hr more to go 32km upside than to return downstream to the same spot. find the speed of the stream?

Answer 1

this may help u.......

Answer 2

Speed of the motor boat = 24 km/h

Speed of the stream = x km/h

Upstream:

Speed = (24 + x) km/h

Distance = 32 km

Time = Distance ÷ Speed

Time = 32/(24 + x) hours

Downstream:

Speed = (24 - x) km/h

Distance = 32 km

Time = Distance ÷ Speed

Time = 32/(24 - x) hours

Solve x:

The difference in duration is 1 hour

32/(24 - x)  -  32/(24 + x) = 1

32(24 + x) - 32(24 - x) = (24 + x)(24 - x)

768 + 32x - 768 + 32x = 24² - x²

x² + 64x - 576 = 0

(x - 8) (x + 72) = 0

x = 8 or x = -72 (rejected, speed cannot be negative)

Answer: The speed of the stream is 8 km/h