SOLUTION: I have a hard time with word problems, and would like some detailed explanation of how to solve this. Thanks, Sue You pay a certain long distance rate that depends on your numb

Algebra ->  Functions -> SOLUTION: I have a hard time with word problems, and would like some detailed explanation of how to solve this. Thanks, Sue You pay a certain long distance rate that depends on your numb      Log On


   



Question 425503: I have a hard time with word problems, and would like some detailed explanation of how to solve this. Thanks, Sue
You pay a certain long distance rate that depends on your number of minutes talked. If you talk from 0 to 700 minutes, you pay 20 cents a minute. If you talk 701 to 1500 minutes, you pay 12 cents a minute. If you talk anything over 1500 minutes, you pay 8 cents a minute.
a. Is the number of minutes you talk a function of your long distance rate?
b. Is your long distance rate a function of the number of minutes you talk?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(a) is not true
(b) is true
This is a cause and effect problem. I like to think
of something much easier, like:
(a) Is plant growth a function of rainfall
or
(b) Is rainfall a function of plant growth?
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You can write it mathematically like:
F(rainfall) = plant growth
This says plant growth is caused by rainfall
If I said
F(plant growth) = rainfall
Now I'm saying rainfall is caused by plant growth
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When you make a graph, you put the cause on the horizontal axis
and you put the result on the vertical axis.
So, in your problem:
Number of minutes is on the horizontal (cause)
Long distance rates are on the vertical (result)