Question

2. The speed of a boat in still water is 15 km/h. It can go 30 km upstream and return
downstream to the original point in 4 hours 30 minutes. Find the speed of the stream
[Ans. Speed of stream = 5 km/h​

Answer 1

Answer:

Step-by-step explanation:Let speed of stream = x km/h

∴ Downstream speed = (15+x) km/h

∴ Upstream speed = (15-x) km/h

∴ 30/(15+x) + 30/(15-x) = 4 1/2

→ 900/225-x² = 9/2

→ 9x² = 225

→ x² = 25

→ x = 5

∴ Speed of stream = 5 km/h

Answer 2

≡QUESTION≡

The speed of a boat in still water is 15 km/h. It can go 30 km upstream and return  downstream to the original point in 4 hours 30 minutes. Find the speed of the stream.

                                                                                       

║⊕ANSWER⊕║

Let speed of stream = x km/h

Downstream speed = (15+x) km/h

Upstream speed = (15-x) km/h

30/(15+x) + 30/(15-x) = 4 1/2

900/225-x² = 9/2

9x² = 225

x² = 25

x = 5

∴ Speed of stream = 5 km/h