Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [ratio]

For questions concerning the ratio of a certain quantity to another.

In mathematics, a ratio is a relationship between two quantities indicating how many times the first number contains the second. For example, if a bowl of fruit contains eight oranges and six lemons, then the ratio of oranges to lemons is eight to six (that is, $8:6$, which is equivalent to the ratio $4:3$). The numbers compared in a ratio can be any quantities of a comparable kind, such as objects, persons, lengths, or spoonfuls. A ratio is written "$a$ to $b$" or $a:b$, or sometimes expressed arithmetically as a quotient of the two.

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Width and height ratio of object in image

I hope I ask this in the correct place. How do I get the width and height ratio of for example a sheet of paper (or some other rectangular thing) from a image. I have built a program that that changes the perspective a paper in a image, but I don't…
Elli
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How do you do this *without* using a calculator? The ratio of three numbers is $3\frac{1}{3}:4\frac{1}{5}:6\frac{1}{8}$

The ratio between three numbers is: Three and one third: Four and one fifth: Six and one eighth and the sum of the numbers is $4197$. What are the three numbers? Using a calculator, I would just add up the numbers which equals $13\frac{79}{120}$,…
Little Black Dog
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Problem with the answer of a basic ratio problem

Here is the solved example. The answer given is 175, but my calculation comes out to be 375. I thought that it was just a typo, but it has been written twice, so I'm not sure. What am I doing wrong?
Always Learning Forever
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Proving Ratios And Proportions

Help me solve this problem! I have tried it many times but nothing appeared. This is the question: If a:b=c:d=e:f, prove that each is equal to (a+c-e):(b+d-f).
Wilson Royce Ong King
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Contradictory definitions of ratio

How is the word ratio defined? I know of two different interpretations of the term ratio, and they are somewhat contradictory. They are: 1) The Reynolds number is the ratio of inertial force to viscous force. It may be defined $Re={Ul}/{\nu}$. 2)…
Chogg
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Should ratio definition have these words, of the same kind?

This is the definition of ratio that is on Wikipedia. “a ratio is a relationship between two numbers of the same kind” Considering the ratio of a moving distance to the fuel amount in a vehicle, I think it would be better if the definition were…
Listenever
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How To Solve a Ratio Equation

This question actually comes from backyard composting. When choosing materials to compost the ideal ratio of Carbon to Nitrogen of the raw materials to make compost is 30:1. There are basically no materials that are 30:1 naturally, so you have to…
Randy
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Finding a combined ratio from two other ratios

So I have a problem with ratios that I need to sort out. I want to know how much of each of two types of food I need to eat in order to get a fixed amount of protein and carbs. an example... I want to eat 33g of protein and 44g or carbs in one meal…
user141288
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Need help solving a question that includes ratios

Three groups, Group A, Group B, Group C, of Sam's friends decided to buy a watch as a memorable gift for his birthday. They contributed 1200 AED in the ratio of 3:4:5. How much did each group contribute?
Majid Saeed Alshamsi
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Adjusted nominator for a more reflective ratio change

Two variables change every year, e.g. $a_1=500$, $a_2=600$ and $b_1=1000$ and $b_2=800$. Their ratio change is $$YoY=a_2/b_2-a_1/b_1=600/800-500/1000=0.25$$ The negative change in the denominator is a negative event and I want to reflect this, so…
balintd
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Direct and Indirect relation concept

Que - 100 million bacteria can completely decompose a garbage dump in 15 days and 60 million bacteria can do so in 30 days. If same quantity of garbage is added to the initial quantity of the dump everyday, how many bacteria will be required to…
Anuraj
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Divided Diamonds : a proportionality & ratio problem

Problem For stones of the same quality (e.g. the same colour), the monetary value of a diamond is proportional to the square of its mass (i.e. $C\propto M^2$). Find the monetary loss ($\Delta C$) incurred by laser-cutting a diamond worth $C_0$ into…
burgler
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Find the ratio of recursive integrals

Given $ I_n = \int_0^{\pi/2} \sin^n\theta d\theta $, the recursive formula can be found as $$ I_n = \frac{n-1}{n}I_{n-2} $$ The lecture notes later state that $$ \frac{I_{2n-1}}{I_{2n+1}} = 1 + \frac{1}{2n} $$ When I try to calculate the ratio based…
tudou
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Find LRT and rejection

enter image description here For each of the n independent individuals, there are two measures of interest:xi which is some known value, and Yi which is a random variable distributed as N(α+βdo,σ^2)
林柔瑄
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How can I round up a decimal number to the nearest whole multiple of the same number?

I want to round up a number with a decimal into the nearest whole number that is also a multiple of it. For example we take the number 1.7777778 (16/9) and we round it up the way I want to we should get 16. which is a way I could calculate aspect…
Confused monkey
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