# Questions tagged [percentages]

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.

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### Minimum Population for Rounded Percent Increase.

I recently saw an infographic comparing growth in different government sectors in my home country. The graphic decided to represent growth as whole number percent increases, with no more information ...
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### Average item cost [closed]

So let's say I can open up crates that have balls in it, but the amount of balls received from each crate has different percentage probability. As shown bellow: ...
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### Finding the percentage change in the slope with the correct plus or minus symbol.

I am trying to build a formula with the data that I have below. The formula will be embedded in a Arduino sketch. Column A is the time stamp and Column B is my voltage value. Column C is a threshold ...
1 vote
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### Discrepancy between the average annual return and the actual stock price

I would really appreciate it if somebody can help me with the math on this one. I feel the need to apologize in advance if this errs on the dumb side. If somebody could walk me through this and make ...
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1 vote
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### Brainfreeze! reduce a number by a percentage so that the number after X iterations is below 1 [closed]

I am having a sort of brainfreeze or cannot express the mathematical formula for the following: I have a Natural Number X and I want to reduce it by a Percentage e.g 4% Y times that after Y iterations ...
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### 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 ...
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On the package of cookies Martino reads that the energy value of 100 grams of the product is 400 kcal; moreover, a single cookie, whose weight is 25 grams, contributes 5 percent to the individual ...
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### Percentage Similarity within Range

I am trying to calculate the similarity between two times. In C# I'd get these values using something like TimeStamp.Ticks; in general, I'm thinking of some ...
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### Calculating percentage of a profit

399 is the amount you will gain if you invest 345 Therefore profit is 399 - 345 = 54 I want to express profit as percentage of the amount that you'll get back but I'm not sure why 2 methods give ...
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### % of unknown number when trying to find unknown number

I'm working on a spreadsheet for my small real estate business and I'm stuck on a math problem. I want to find the minimum rent I can charge for a property to still break even. I know the monthly ...
1 vote
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### How do I use math to calculate the percentages of multiple random events happening

I'm creating a mod to a video game that will list the percent chance of an event happening. I know how to get individual percentages, but not a total percentage of the events. The Problem: So there is ...
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### Contribution of a single value in a Division of Sums

I need to isolate contribution of a single entity in a Division of Sums as shown below. For example, find the contribution of variable a in the following: (a 1 + b ...
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### Determine point from one aspect ratio to an equivlent aspect ratio

I am working on a code program and get the X and Y coordinates of my cursor. My aspect ratio is 1280x720 and a point I am using for an example is (710, 300) however my x and y values must be 0.0-1.0, ...
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### The number of bacteria in a culture is 1000 and this number increases by 250% every two hours. How many bacteria is present after 24 hours?

Had to find a recurrent relation for this problem and then find the explicit formula to get our bacteria amount after 24 hours. I got the question wrong because my recurrence relation was wrong. ...
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### Converting a ratio into percentage.

As per many websites and text books, 3:4 converted into % is 75%. But as per my understanding, its not. If 3:4 is the ratio of boys and girls in a class, then it means that 3 out 7 are boys and 4 out ...
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### Strange behavior and output from percent function in calculator. Can some explain to me what is happening here? [closed]

I'm building a calculator web app as a learning exercise, and when I got to the percent function I noticed something strange. While entering this input on an iPhone calculator - I didn't have a ...
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### 2016-2022 inflation. Mismatch using CPI and percentage multiplication [duplicate]

*** sorry for double question *** Please, i'm going crazy :) This is my problem and i hope you can help me. I need to calculate total inflation for the period 2016-2022 in a certain coutry. The ...
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### Problem with inflation 2016-2022 : CPI and percentage mismatch

this is my problem and i hope you can help me. I need to calculate total inflation for the period 2016-2022 in a certain coutry. The problem is that I can't match the data, obtaining the same result ...
1 vote
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### How to calculate the chances of 2 chances/odds being true…?

I was thinking about making a JavaScript chances percentage calculator that would combine to chances to make one… If you don’t know what I mean.. Say: 5% of the world population can solve a Rubik’s ...
1 vote
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### calculating total weekly percentage increase when new datasources also added

I'm not sure if I can accurately describe my situation. We have data (a starting value usually between 30000 and 50000) from four different sources, and each day the values for each source increases ...
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### How does this 2D6 probability math make sense? [closed]

I have a question about understanding the math to a previous question I had posed (answered successfully). Link at the bottom. The question is how does it make sense that rolling a 2D6 Die consisting ...
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### What is the chance of getting same decimals of percentage 4 times in a row with RNG?

I was rolling some random percentage with RNG between 0 and 1; if you multiply the result to 100, you're getting the percentage between 0 and 100, decimal amount was 4. And then I got 0.7171% the ...
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### Percentage within each other?

Consider finding what percentage the values $15$ and $23$ are within each other. How would I calculate this? To me, it is not clear whether to do $\frac{23-15}{15}$ or to do $\frac{23-15}{23}$ to find ...
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### Adding percentages to a number

If I want to multiply with multiple percentage increases, I convert it to decimal and then calculate. Example: 1 * 1.4 * 1.2 = 1.68 Now, I came across someone on reddit who calculates it the following ...
1 vote
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### Fractions and percentages

I have a question for my sons homework that he and I are struggling to solve. Janet spent $\frac{1}{5}$ of her salary and an additional 146 on food every month. She then spent $\frac{1}{3}$ of her ...
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### How to calculate the percentage to add to a increasing amount to get a total in a fixed time? [closed]

Let say I want to earn 2000€ with an investment done each day in a year (i.e. a percentage every day, for 365 days). I have a initial budge of X amount. Which percentage (per day) I have to gain to ...
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### Why do I get a different answer when I use the total percent?

I feel like this should be obvious, but I am still struggling to wrap my head around this: Suppose Bill has $1000$ apples and $2000$ oranges, while Sue has $1500$ apples and 500 oranges. Now suppose ...
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### If I know the ratio of two variable differences, how to write it as a percentage increase?

I know that $\dfrac{\delta x}{ \delta y} = 5.8,$ meaning that the change in $x$ is $5.8$ times the change in $y.$ Is there a way to write this as a percentage increase? For example, there is a '$p$' ...
1 vote
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### How to make logical sense of following problem with ratios/percentages

I have the following variables L M T L1 M1 T1 L2 M2 T2 L3 M3 T3 L4 M4 T4 where $L+M=T$ I want to calculate an approximate value for the 4s using the ratio between the 2s and 1s, and then ...
1 vote
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### Appropriate Mathematical Symbol for Percentage Representation: $=$ or $\implies$?

I am unsure if this is the appropriate forum for my question, but I have been struggling to articulate it accurately while searching for a solution online. I am uncertain if I am overthinking the ...
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### How to Calculate the Total Probability of Success from Weighted Variables

I am trying to determine the total percentage of this project being successful. We have about 5 different variables which each carry a different weight. The weight of the variable is how critical it ...
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### Reducing a scaling formula [closed]

$X$ can be between 4 and 10 For every number $X$ is below 10, reduce $Y$ by 5% For example, if $X=7$, then $Y'=0.85Y$ (100 - (5 * (10 - X))) * Y / 100 Can I reduce ...
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### How can I reverse the percentage of a number? [closed]

For example, I have an x ​​number. 15% of x number is taken as discount and subtracted from x number. Then 10% of the remaining result is added to the result as tax and the result is found. Let's call ...
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1 vote
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### Percent Down / Up curve

If I create a curve where, starting from a given $Y_{0}$, each new $y$ is down of $p$% and then up of $p$% (that is, the same percentage), is it known by some name? What could be suitable equations to ...
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### Simple looking but difficult fraction problem

If I use my phone continuously, its battery will last for 6 hours. If I do not use my phone, its battery will last for 60 hours. On a plane trip, I use my phone for only half of the trip. The phone is ...
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### Depreciation of value

I need help finding out at which percentage a car's value decreases by each year. It changes by the same percentage each year, and by year $5$ it's value has decreased from $325000$ to $70000$. By ...