Question

a paddling canoeist took 2 h to travel 12 km down a river, with the current. It took 4 h to do the return trip up the river, against the current. What was the speed of the current

Answer 1

Answer: The speed of the current is 1.5 km/h .

Explanation:

Let x = speed of current and y = speed of canoe.

Since ,
`\text{Speed}=\frac{\text{Distance}}{\text{Time}}`

As per given , we have

`x+y=(12)/(2)\\\\ x+y=6......................(1)`

`y-x=(12)/(4)\\ y-x=3...............(2)`

Adding (1) and (2) , we get

`2y=9\\\Rightarrow\ y=(9)/(2)=4.5`

Put value of y in (1) , we get

`x+4.5=6\\\Rightarrow\ x=1.5`

Hence, the speed of the current is 1.5 km/h .