Question

Trudi and Sean are on a river canoeing. Because of the current of the river, their downstream rate is 250% of their upstream rate. They canoe 3 mi upstream and then return to their starting point.

a. Write an expression for the amount of time Trudi and Sean spend canoeing.
b. If their upstream rate is 2mi/h, how much time do Trudi and Sean spend canoeing.

Answer 1

a. Write an expression for the amount of time Trudi and Sean spend canoeing.

Let y be the total time taken to canoe and x be the amount of time taken to row upstream.

y= x + x/2.5

x is the time taken to row upstream, x/2.5 is the time taken to row downstream. Since downstream will be 250% faster, the time taken will be shorter in that proportion also.

b. If their upstream rate is 2mi/h, how much time do Trudi and Sean spend canoeing.
Give upstream rate is 2mi/h.

Find x, the time taken to row upstream. Since they canoe upstream for 3mi and their rate is 2mi/h

Time taken is 3/2 = 1.5 hrs.

substitute x = 1.5 to equation of y

y= 1.5 + 1.5/2.5
=1.98 hrs

Answer 2

how did you get 1.98hr?

Answer 3

y= 1.5 + 1.5/2.5 =1.98 hrs

Answer 4

isn't 1.5 divided by 2.5= 0.6?

Answer 5

Hmm i don't know how i made that error, punch calculator wrongly. Yep you are right!