SOLUTION: If z varies inversely as w, and z=20 when w=0.2, find z when w=20.

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Question 1201775: If z varies inversely as w, and z=20 when w=0.2, find z when w=20.
Found 3 solutions by mananth, greenestamps, josgarithmetic:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
inverse proportion
+z%28alpha%29%281%2Fw%29
z= k/w
z=20 when w=0.2
plug in to find k
20=k/0.2
k=0.2*20 = 4
when w=20.k=4
find z plug and get it


Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


There is no need to be formal with this and find the constant of variation, as the other tutor did.

Inverse variation means the product of the two numbers is constant. That makes this example trivial:

"20 times 0.2 is equal to 20 times what number?"

ANSWER (obvious!): 0.2

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
k, the variation constant

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z varies inversely as w
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z=k%2Fw



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z=20 when w=0.2
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zw=k
k=zw
k=%2820%29%280.2%29
k=4

Formula is therefore highlight%28z=4%2Fw%29.