A percentage is a number or ratio expressed as a fraction of $100$. It is often denoted using the percent sign, "$%$", or the abbreviation "$\mathrm{pct}$." -Wikipedia. Percentages are used when describing portions or proportional changes.
Questions tagged [percentages]
1440 questions
29
votes
6 answers
Misunderstanding of percentage increase
If something increase $50$ to $200$, I know that it is $400\%$ increment using common sense.
I can get this using $\dfrac{200}{50}\times 100\% = 400\%$.
If something increase $50$ to $52$, I know that it is $4\%$ increment using common sense.
But…
I am the Most Stupid Person
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28
votes
3 answers
What does "X% faster" mean?
I was reading something today that was talking in terms of 10%, 100% and 1000% faster. I assumed that 10% faster means it takes 10% less time (60 seconds down to 54 seconds).
If that is correct wouldn't 100% faster mean 0 time and 1000% mean…
Abe Miessler
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18
votes
17 answers
Why does $0.75 \times 1.25$ equal $0.93$ and not $1$?
If percentage points can equal decimal points, then $1.25$ should equal $125$% when multiplying $1.25$ by any number.
Therefore $125$% of $0.75$ should equal $1$ if $0.75$ is also $75$% of $1$.
Am I missing something super obvious here or…
16
votes
4 answers
What is the difference between faster by factor and faster by percent?
I don't understand the difference between faster by factor versus faster by percent. For example,
Machine A Execution Time: 5.106 ms
Machine B Execution Time: 0.851 ms
Obviously, machine B is faster 4.255 ms. Now, I want to display how much faster…
RandomDuck.NET
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15
votes
14 answers
Does 17% have to be equal to 0.17?
I have a friend who believes that 17% doesn't have to be equal to 0.17. Even though he says that 17% is equal to 0.17 on its own, he says that 17% at any other time is not equal to 0.17, referring to the argument that $17\%x \neq 0.17$. No matter…
Jonathan Spirit
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10
votes
8 answers
How can something be greater than $100\%$?
Apologies, my mathematics is poor but I saw an advert recently which said:
Up to $350\%$ more likely to quit
How can something be greater than $100\%$? It can't be can it?
user401126
9
votes
1 answer
Find what percent X is between two numbers?
So I am working on a problem for a program I am making...
Say I have two numbers: 10 and 100, than I have a variable. How would i find what percent the variable is between the two numbers?
So:
45 is 50% between 10 and 100
17.5 is 25% between 10…
user3040452
- 93
9
votes
2 answers
Can arbitrary values be reached by repeatedly adding or subtracting a fixed percentage of the current value?
Let $G$ and $X$ be positive integers, and $P$ be a rational value in $(0, 1)$. Two operations may be performed on $X$ to modify its value:
$$X \leftarrow \lfloor X \cdot (1 + P) \rfloor$$ and $$X \leftarrow \lfloor X \cdot (1 - P) \rfloor$$
Is it…
user282078
6
votes
1 answer
How is percentage difference between two numbers defined?
When comparing two quantities, say $x_1, x_2$ or something casually, I frequently use the phrase "they're within X%" but I use it rather loosely because mathematically, to compute the percentage difference it depends on whether you use $x_1, x_2$ as…
roulette01
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6
votes
4 answers
What is the percentage increase to any value when initial value is 0?
This is a very simple maths problem, which doesn’t seems simple to me when I just put some extra thoughts on it. So need to borrow some extra brains for this.
Question:
If cost of coffee in my office was Dollar 0 till yesterday and today it is…
kishoredbn
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6
votes
4 answers
How to calculate what percentage of 228 is 199?
I'm a simple man who doesn't know much math. Sometimes in my work and life I've to do math calculations. Today was one of those days and I've spent the last hour trying to figure this out.
Look. Let's say the old pricing of a set of screwdrivers…
bodacydo
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5
votes
6 answers
Calculating a 20% discount by multiplying by 0.8333?
I've been looking at some discounted prices of goods.
They are listed with a $20\%$ discount, so to work this out I did:
$$ \$25.45 \cdot 0.8333 = \$21.21. $$
But their total was $20.34$, which I presume they got by doing $25.42 \cdot 0.8$.
To…
sam
- 221
5
votes
3 answers
10% lower and 10% higher of 100
I'm confused about how to get the $10\%$ higher and $10\%$ lower of $100$. I'm alone I don't know if my idea is correct. My idea is $10\%$ higher of $100$ is $110$, then the $10\%$ lower of $100$ is $90$, then the range $10\%$ higher and $10\%$…
4
votes
2 answers
Finding potentially missed days based on amount of "Downloads" in a Month
Not sure if this is the right place(If not, where?) to ask this, but I am trying to come up with a formula based on a scenario.
There is a website where users can pay to get a certain amount of "Downloads" per month. The max amount of downloads is…
Etra
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4
votes
1 answer
Intuitively, why is X% of Y = Y% of X?
I didn't spot this trick until I read this:
LPT: X percent of Y is equal to Y percent of X.
I know that multiplication is commutative; obviously,
$\dfrac{X}{100}Y= X\dfrac{Y}{100}$. But this algebra doesn't betray the intuition that I feel I'm…
user53259