## Jonathon and Samantha row their canoe 28 miles downstream in 2 hours. After a​ picnic, they row back upstream. After 3 hours they only trave

Question

Jonathon and Samantha row their canoe 28 miles downstream in 2 hours. After a​ picnic, they row back upstream. After 3 hours they only travel 12 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.

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2 days 2021-09-11T18:00:59+00:00 1 Answer 0

1. Answer: the speed at which Jonathon and Samantha can row in still water is 9 mph

Step-by-step explanation:

Let x represent the speed of the canoe in still water.

Let y represent the speed of the river’s current.

Jonathon and Samantha row their canoe 28 miles downstream in 2 hours. Assuming they rowed with the current, the total speed would be (x + y) mph

Distance = speed × time

Distance travelled downstream is expressed as

28 = 2(x + y)

Dividing through by 2, it becomes

14 = x + y – – – – – – – -1

After a​ picnic, they row back upstream. After 3 hours they only travel 12 miles. Assuming they rowed against the current, the total speed would be (x – y) mph

Distance travelled upstream is expressed as

12 = 3(x – y)

Dividing through by 3, it becomes

4 = x – y – – – – – – – -2

Adding equation 1 and equation 2, it becomes

18 = 2y

y = 18/2

y = 9 mph