Practicing Success
A boat covers 64 km upstream in 8 hours and 120 km downstream in 12 hours. What is the speed (in m/s) of the boat in still water? |
2.5 2 3.5 3 |
2.5 |
The speed of the boat in still water is = (Speed of the boat in downstream + Speed of the boat in upstream) $\div$ 2 The boat covers 64 km upstream in 8 hours So, Speed of the boat in upstream = 8 km/h Also, the boat covers 120 km downstream in 12 hours Speed of the boat in downstream = 10 km/h The speed of the boat in still water = (10 + 8) $\div$ 2 = 9 km/h or 9 $\times$ \(\frac{5}{18}\) = 2.5 m/s |