Why can the Potato Paradox be quantified as $0.99⋅100−0.98(100−w)=w$?
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I understand the two Simple Explanations, but not Algebraic Explanation Method 2. I substitute $x$ in Wikipedia with $w$, as $x$ is already used for another method.
The weight of water in the fresh potatoes is $0.99 ⋅ 100.$
If $w$ is the weight of water lost from the potatoes when they dehydrate then $color{green}{0.98 ( 100 − w )}$ is the weight of water in the dehydrated potatoes. Therefore:
$0.99 ⋅ 100 color{darkorange}{−}color{green}{0.98 ( 100 −w )} = color{red}{w}. tag{?}$
Why $color{orange}{−}$ here, when we added (and never subtracted) in the LHS in Algebraic Explanation Method 1?
How's the LHS devised? I understand the 0.98, as the problem statement requires 98% water after dehydration. But I would've never dreamed or excogitated of $color{green}{0.98 ( 100 −w )}$?
Why do we make the LHS equal to $color{red}{w}$? I would've never excogitated equating the LHS with $color{red}{w}$?
I have a BA in Economics, and already know how $99 − 0.98 ( 100 − w ) = w iff 1 + 0.98x = x$.
percentages
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add a comment |
$begingroup$
I understand the two Simple Explanations, but not Algebraic Explanation Method 2. I substitute $x$ in Wikipedia with $w$, as $x$ is already used for another method.
The weight of water in the fresh potatoes is $0.99 ⋅ 100.$
If $w$ is the weight of water lost from the potatoes when they dehydrate then $color{green}{0.98 ( 100 − w )}$ is the weight of water in the dehydrated potatoes. Therefore:
$0.99 ⋅ 100 color{darkorange}{−}color{green}{0.98 ( 100 −w )} = color{red}{w}. tag{?}$
Why $color{orange}{−}$ here, when we added (and never subtracted) in the LHS in Algebraic Explanation Method 1?
How's the LHS devised? I understand the 0.98, as the problem statement requires 98% water after dehydration. But I would've never dreamed or excogitated of $color{green}{0.98 ( 100 −w )}$?
Why do we make the LHS equal to $color{red}{w}$? I would've never excogitated equating the LHS with $color{red}{w}$?
I have a BA in Economics, and already know how $99 − 0.98 ( 100 − w ) = w iff 1 + 0.98x = x$.
percentages
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1
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(original weight due to water) - (weight due to water, after dehydration) = (weight lost)
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– Zubin Mukerjee
Jan 23 at 6:49
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You really need to edit the question to include some missing details - otherwise it is simply unclear where the 0.98 figure comes from. You have potatoes which are 99% water and they dehydrate until they are 98% water. How much weight do they lose? The equations are simply computing the weight of water before and after using the proportions given. The difference is the change in weight.
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– Mark Bennet
Jan 23 at 7:02
add a comment |
$begingroup$
I understand the two Simple Explanations, but not Algebraic Explanation Method 2. I substitute $x$ in Wikipedia with $w$, as $x$ is already used for another method.
The weight of water in the fresh potatoes is $0.99 ⋅ 100.$
If $w$ is the weight of water lost from the potatoes when they dehydrate then $color{green}{0.98 ( 100 − w )}$ is the weight of water in the dehydrated potatoes. Therefore:
$0.99 ⋅ 100 color{darkorange}{−}color{green}{0.98 ( 100 −w )} = color{red}{w}. tag{?}$
Why $color{orange}{−}$ here, when we added (and never subtracted) in the LHS in Algebraic Explanation Method 1?
How's the LHS devised? I understand the 0.98, as the problem statement requires 98% water after dehydration. But I would've never dreamed or excogitated of $color{green}{0.98 ( 100 −w )}$?
Why do we make the LHS equal to $color{red}{w}$? I would've never excogitated equating the LHS with $color{red}{w}$?
I have a BA in Economics, and already know how $99 − 0.98 ( 100 − w ) = w iff 1 + 0.98x = x$.
percentages
$endgroup$
I understand the two Simple Explanations, but not Algebraic Explanation Method 2. I substitute $x$ in Wikipedia with $w$, as $x$ is already used for another method.
The weight of water in the fresh potatoes is $0.99 ⋅ 100.$
If $w$ is the weight of water lost from the potatoes when they dehydrate then $color{green}{0.98 ( 100 − w )}$ is the weight of water in the dehydrated potatoes. Therefore:
$0.99 ⋅ 100 color{darkorange}{−}color{green}{0.98 ( 100 −w )} = color{red}{w}. tag{?}$
Why $color{orange}{−}$ here, when we added (and never subtracted) in the LHS in Algebraic Explanation Method 1?
How's the LHS devised? I understand the 0.98, as the problem statement requires 98% water after dehydration. But I would've never dreamed or excogitated of $color{green}{0.98 ( 100 −w )}$?
Why do we make the LHS equal to $color{red}{w}$? I would've never excogitated equating the LHS with $color{red}{w}$?
I have a BA in Economics, and already know how $99 − 0.98 ( 100 − w ) = w iff 1 + 0.98x = x$.
percentages
percentages
asked Jan 23 at 6:41
Amanda d'HalluinAmanda d'Halluin
38116
38116
1
$begingroup$
(original weight due to water) - (weight due to water, after dehydration) = (weight lost)
$endgroup$
– Zubin Mukerjee
Jan 23 at 6:49
$begingroup$
You really need to edit the question to include some missing details - otherwise it is simply unclear where the 0.98 figure comes from. You have potatoes which are 99% water and they dehydrate until they are 98% water. How much weight do they lose? The equations are simply computing the weight of water before and after using the proportions given. The difference is the change in weight.
$endgroup$
– Mark Bennet
Jan 23 at 7:02
add a comment |
1
$begingroup$
(original weight due to water) - (weight due to water, after dehydration) = (weight lost)
$endgroup$
– Zubin Mukerjee
Jan 23 at 6:49
$begingroup$
You really need to edit the question to include some missing details - otherwise it is simply unclear where the 0.98 figure comes from. You have potatoes which are 99% water and they dehydrate until they are 98% water. How much weight do they lose? The equations are simply computing the weight of water before and after using the proportions given. The difference is the change in weight.
$endgroup$
– Mark Bennet
Jan 23 at 7:02
1
1
$begingroup$
(original weight due to water) - (weight due to water, after dehydration) = (weight lost)
$endgroup$
– Zubin Mukerjee
Jan 23 at 6:49
$begingroup$
(original weight due to water) - (weight due to water, after dehydration) = (weight lost)
$endgroup$
– Zubin Mukerjee
Jan 23 at 6:49
$begingroup$
You really need to edit the question to include some missing details - otherwise it is simply unclear where the 0.98 figure comes from. You have potatoes which are 99% water and they dehydrate until they are 98% water. How much weight do they lose? The equations are simply computing the weight of water before and after using the proportions given. The difference is the change in weight.
$endgroup$
– Mark Bennet
Jan 23 at 7:02
$begingroup$
You really need to edit the question to include some missing details - otherwise it is simply unclear where the 0.98 figure comes from. You have potatoes which are 99% water and they dehydrate until they are 98% water. How much weight do they lose? The equations are simply computing the weight of water before and after using the proportions given. The difference is the change in weight.
$endgroup$
– Mark Bennet
Jan 23 at 7:02
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
Perhaps
$$
0.99cdot 100=w+0.98(100-w)
$$
is more intuitive: The total amount of water is the same before and after the evaporation. Thus the weight of water in the potatoes before the evaporation is equal to the weight of evaporated water, $w$, plus the weight of the water that's left in the potatoes, $0.98(100-w)$.
$endgroup$
add a comment |
$begingroup$
You have the original water weight equal to $0.99cdot 100$. The total weight of the potatoes before is $100$, after you lose $w$ water you have the total weight $100-w$. Out of that, $98%$ is water, so the water left is $0.98(100-w)$. You can probably better understand if you switch the order of the terms, and you write "original-lost=final": $$0.99cdot 100-w=0.98(100-w)$$ This is the same equation, I just moved some terms around.
$endgroup$
add a comment |
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2 Answers
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active
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2 Answers
2
active
oldest
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$begingroup$
Perhaps
$$
0.99cdot 100=w+0.98(100-w)
$$
is more intuitive: The total amount of water is the same before and after the evaporation. Thus the weight of water in the potatoes before the evaporation is equal to the weight of evaporated water, $w$, plus the weight of the water that's left in the potatoes, $0.98(100-w)$.
$endgroup$
add a comment |
$begingroup$
Perhaps
$$
0.99cdot 100=w+0.98(100-w)
$$
is more intuitive: The total amount of water is the same before and after the evaporation. Thus the weight of water in the potatoes before the evaporation is equal to the weight of evaporated water, $w$, plus the weight of the water that's left in the potatoes, $0.98(100-w)$.
$endgroup$
add a comment |
$begingroup$
Perhaps
$$
0.99cdot 100=w+0.98(100-w)
$$
is more intuitive: The total amount of water is the same before and after the evaporation. Thus the weight of water in the potatoes before the evaporation is equal to the weight of evaporated water, $w$, plus the weight of the water that's left in the potatoes, $0.98(100-w)$.
$endgroup$
Perhaps
$$
0.99cdot 100=w+0.98(100-w)
$$
is more intuitive: The total amount of water is the same before and after the evaporation. Thus the weight of water in the potatoes before the evaporation is equal to the weight of evaporated water, $w$, plus the weight of the water that's left in the potatoes, $0.98(100-w)$.
answered Jan 23 at 6:52
ArthurArthur
118k7117200
118k7117200
add a comment |
add a comment |
$begingroup$
You have the original water weight equal to $0.99cdot 100$. The total weight of the potatoes before is $100$, after you lose $w$ water you have the total weight $100-w$. Out of that, $98%$ is water, so the water left is $0.98(100-w)$. You can probably better understand if you switch the order of the terms, and you write "original-lost=final": $$0.99cdot 100-w=0.98(100-w)$$ This is the same equation, I just moved some terms around.
$endgroup$
add a comment |
$begingroup$
You have the original water weight equal to $0.99cdot 100$. The total weight of the potatoes before is $100$, after you lose $w$ water you have the total weight $100-w$. Out of that, $98%$ is water, so the water left is $0.98(100-w)$. You can probably better understand if you switch the order of the terms, and you write "original-lost=final": $$0.99cdot 100-w=0.98(100-w)$$ This is the same equation, I just moved some terms around.
$endgroup$
add a comment |
$begingroup$
You have the original water weight equal to $0.99cdot 100$. The total weight of the potatoes before is $100$, after you lose $w$ water you have the total weight $100-w$. Out of that, $98%$ is water, so the water left is $0.98(100-w)$. You can probably better understand if you switch the order of the terms, and you write "original-lost=final": $$0.99cdot 100-w=0.98(100-w)$$ This is the same equation, I just moved some terms around.
$endgroup$
You have the original water weight equal to $0.99cdot 100$. The total weight of the potatoes before is $100$, after you lose $w$ water you have the total weight $100-w$. Out of that, $98%$ is water, so the water left is $0.98(100-w)$. You can probably better understand if you switch the order of the terms, and you write "original-lost=final": $$0.99cdot 100-w=0.98(100-w)$$ This is the same equation, I just moved some terms around.
answered Jan 23 at 6:59
AndreiAndrei
13.1k21230
13.1k21230
add a comment |
add a comment |
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1
$begingroup$
(original weight due to water) - (weight due to water, after dehydration) = (weight lost)
$endgroup$
– Zubin Mukerjee
Jan 23 at 6:49
$begingroup$
You really need to edit the question to include some missing details - otherwise it is simply unclear where the 0.98 figure comes from. You have potatoes which are 99% water and they dehydrate until they are 98% water. How much weight do they lose? The equations are simply computing the weight of water before and after using the proportions given. The difference is the change in weight.
$endgroup$
– Mark Bennet
Jan 23 at 7:02