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 .

Step-by-step explanation:

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

Since  , $\text{Speed}=\dfrac{\text{Distance}}{\text{Time}}$

As per given , we have

$x+y=\dfrac{12}{2}\\\\ x+y=6......................(1)$

$y-x=\dfrac{12}{4}\\ y-x=3...............(2)$

Adding (1) and (2) , we get

$2y=9\\\Rightarrow\ y=\dfrac{9}{2}=4.5$

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 .