Question

Jonathon and Samantha row their canoe 26 miles downstream in 2 hours. After a picnic, they row back upstream. After 3 hours they only travel 15 miles. Assuming that they canoe at a constant rate and the river's current is constant, find the speed at which Jonathon and Samantha can row in still water.

Answer 1

Answer:9 mph

Explanation:

Given

During downstream it took 2 hr to cover 26 miles

During upstream it took 3 hr to cover 15 miles

Let v be the canoe velocity and
`v_0` be the stream velocity

thus

`2=(26)/(v+v_0)`

`v+v_0=13`------1

and
`3=(15)/(v-v_0)`

`v-v_0=5`--------2

From 1 & 2 we get

2v=18

v=9 mph

`v_0=4 mph`