SOLUTION: Sue walks and jogs to school. She walks at a speed of 5kmh and jogs at a speed of 9kmh. It is 8km to school. She makes it in 1 hour. How far does she jog? I know that d=rt but I

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Question 170955This question is from textbook Introductory Algebra
: Sue walks and jogs to school. She walks at a speed of 5kmh and jogs at a speed of 9kmh. It is 8km to school. She makes it in 1 hour. How far does she jog?
I know that d=rt but I'm drawing a blank on this one.
Thanks
This question is from textbook Introductory Algebra

Found 2 solutions by angel1286, Mathtut:
Answer by angel1286(3) About Me  (Show Source):
You can put this solution on YOUR website!
just set up an equation that adds up the distances traveled:
let x denote the time that it was used walking, then the time for joging cam be denoted as (1-x) because it was one hour of total trip, then use the formula that distance = velocity * time; then the equation looks like:
+5x+%2B+9%2A%281-x%29=8+
5x+%2B+9+-+9x+=+8
+-4x+%2B+9+=+8
-4x=-1
x=.25 then to find out how much she jogs, we multiply 9 * (1-0.25) because that is the time used for joggin and the answer is 6.75

Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
ok.......this isnt written very well but what they are getting at is she walked a portion and jogged a portion of the trip(8km) to school. d=rt. lets call the distance she walked x and the distance she jogged 8-x. lets the time she walked t and the time she jogged 1-t(1hour altogether). walking rate is 5 and jogging rate is 9
:
x=5t.........eq 1
8-x=9(1-t)...eq 2
:
take x's value from eq 1 and plug it into eq 2
:
8-5t=9(1-t)
:
8-5t=9-9t
:
4t=1
:
t=1%2F4hour she walked
:
we are after distance she jogged so lets find x ...x=5(1/4)=5/4=1.25..distance she walked
:
distance she jogged is 8-x...highlight%288-%281.25%29=6.75%29km