SOLUTION: Yellows vary inversely as grays cubed. When there are 270 yellows, there are 2 grays. How many yellows are present when there are 6 grays? i got 810 and i was just wondering if it
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Question 632189: Yellows vary inversely as grays cubed. When there are 270 yellows, there are 2 grays. How many yellows are present when there are 6 grays? i got 810 and i was just wondering if it is correct Found 2 solutions by solver91311, ankor@dixie-net.com:Answer by solver91311(24713) (Show Source):
Whenever two things are in inverse proportion, when one gets bigger, the other gets smaller -- a lot smaller in this case because yellows vary as the cube of the greys. So one would expect that if the number of greys got 3 times larger, then the number of yellows would get 3 cubed or 27 times smaller rather than 3 times larger. Make sense?
Here's the algebra to back me up:
If yellows greys, then:
I'll leave it up to you to verify that
Now we have a formula that we can use for specific cases:
Plug in
I'll leave the rest of the arithmetic to you.
John
My calculator said it, I believe it, that settles it
You can put this solution on YOUR website! Yellows vary inversely as grays cubed
:
Let k = the constant of the variation.
y =
:
When there are 270 yellows, there are 2 grays.
270 =
k = 8 * 270
k = 2160
:
How many yellows are present when there are 6 grays?
y = 2160/6^3
y = 2160/216
y = 10