word problem
- Thread starter kristen
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- Feb 4, 2004
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Ouch! They were supposed to have covered this material before assigning homework on it! :shock:kristen said:
To learn about ratios, try here. To learn how to translate word problems into variable expressions and equations, try here. To learn how to set up and solve this specific type of exercise, try here. To learn how to solve linear equations, try here. (Obviously, this is much too much material to attempt to explain to you within this environment!)
Once you have learned the necessary background material, please attempt the exercise. If you get stuck, you can then reply with a clear listing of your steps and reasoning so far, starting with your choice of variables and their definitions. For instance:
. . . . .younger now: y
. . . . .older now: (4/3)y
. . . . .younger later: y + 6
. . . . .older later: (6/5)(y + 6) = (4/3)y + 6
Thank you!
D
Deleted member 4993
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I'll do a similar but different problem:kristen said:
the ages of 2 sisters are in the ratio 5:7, but after 10 years the ratio of their ages will be 6:7. find their present age.
Age of sister 1 now = x ....................Age of sister 1 - ten years later = x + 10
Age of sister 2 now = y ....................Age of sister 2 - ten years later = y + 10
Then
the ages of 2 sisters are in the ratio 5:7
x/y = 5/7
x = 5/7 * y........................................................(1)
after 10 years the ratio of their ages will be 6:7
(x+10)/(y+10) = 6/7...........................................(2)
7 * x + 70 = 6y + 60
Using (1)
5y + 70 = 6y + 60
y = 10
Using (1)
x = 50/7
check - use these values of x and y in (2)
(x+10)/(y+10) = (50/7 + 10)/(10 + 10) = (120/7)/(20) = 6/7 ...........checks