# Questions tagged [ratio]

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

701 questions
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### Two parts of first ratio and one part of second ratio

I was preparing for Quantitative aptitude exams and I came across this question of ratios An alloy contains copper and zinc in ratio 5:2 and another alloy contains zinc and tin in the ratio 3:2. ...
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### If $\sin{\alpha}=\frac{8}{17}$ and $\sin{\beta}=\frac{15}{17}$, for acute $\alpha$ and $\beta$, then $\alpha+\beta=\pi/2$

Prove that $\alpha+\beta=\frac{\pi}{2}$, if $\sin{\alpha}=\frac{8}{17}$ and $\sin{\beta}=\frac{15}{17}$, where $0<\alpha<\frac{\pi}{2}$ and $0<\beta<\frac{\pi}{2}$. This is what I did ...
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### what is the selling rate at which all five people earn same amount of money, [on hold]

Five people have oranges in ratio of 1:2:3:4:5 they have to sell the oranges , what is the selling rate at which all five people earn same amount of money, the selling price must be same for all ...
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### How many servings of cereal in 450-gram box?

I am helping my brother with his math again - I need a way to explain this to him!I am ages past this and don't have the time to find an explanation and figured that asking here would be quicker. The ...
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### Ratio between two groups

I want to know among what is the ratio of insured people with disease $x$ to uninsured people with disease $x$. Here are my numbers. Insured, disease $x = 3600$ Uninsured, disease $x = 950$ Insured, ...
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### Trigonometric Ratios and Converse of Pythagoras Theorem Lemma

I am not quite sure what the question is asking here really. I understand the Lemma. Do I prove that $a^2+b^2=1$, using the given expressions for $a$ and $b$? Thank you!
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### How to determine mixing ratio to get desired percentage?

Let's say I have two types of chocolate. Chocolate A contains 70% cocoa and 30% sugar. Chocolate B contains 100% cocoa and no sugar. How can I figure out the exact mixing ratio I need to use to ...
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### I was wondering how I can solve this question as I'm a bit stuck. [closed]

$P, Q$, and $R$ are each mixtures of red and white paint. The percentage by volume of red paint in $P$ is $30\%$. The percentage by volume of red paint in $Q$ is $20\%$. The mixtures $P, Q$, and $R$ ...
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### Excel function to divide a whole number into whole parts, according to a multi-part ratio

Suppose I have a number of objects N, and I want to separate them into three or more buckets according to a known ratio, let's say x : y : z. The value N does not necessarily divide perfectly along ...
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### Determining convergence of series when terms are decreasing by factor less than 1 [duplicate]

Suppose that $a_n > 0$ and that, for n sufficiently large, $$\frac{a_{n+1}}{a_n}\leq 1- \frac{c}{n}$$ for $c>1$ Prove that the series $\displaystyle \sum_{n=1}^{\infty}a_n$ converges. Hint ...
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### Difficult circle geometry question, proof sum of 2 sides ratio equals 1

I have been working on this question for hours on end but not even come close to solving. I have found 2 pairs of similar triangles and an isosceles triangle, and tried to equate the ratio of sides, ...
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### If $\frac{y}{x-z} = \frac{x+y}{z} = \frac{x}{y}$ find the ratio of $x$, $y$ and $z$

I have this question from higher algebra by Hall and Knight: if $\frac{y}{x-z} = \frac{x+y}{z} = \frac{x}{y}$ then find the ratio of x,y and z? There are two answers given for this question, the ...
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### A machine produces B unit goods in A hours… [closed]

A machine produces $b$ unit goods in $a$ hours. How many hours does this machine need to produce $b\cdot c$ unit goods?
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### Value of B in this ratio problem? [closed]

a,b,c integers $a+b+c=45$ $\frac{a}{b}=\frac{3}{2}$ $\frac{b}{c}=\frac{4}{5}$ b=?
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### The ratio between positive/negative numbers

I am creating a model that compares multiple data points of two attributes and compares them vs one another as a percentage of 100. So for instance, comparing the values A=1.24 v B=0.44 would be: ...
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### What formula would I use to scale multiple images to fit in a canvas?

I’m trying to tile random square images with a fixed width and height on a rectangular canvas. The number of images that need to be tiled is a variable. All of the images need to show on the canvas. ...
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### How to find points on a graph from ratios

A bag of 75 balls has a ratio of red balls to green balls is 2:7. If y, which is the number of red balls is graphed as a function of x, which is the number of green balls, which set of points will the ...
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### ratio calculation problem, can someone help?

the problem is like this : an online recipe calls for 2 liter of 3% bleach to 50 liter of water. so, how many liter of 11% bleach to 50 liter of water ? anybody able to teach me ? thanks andrew
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### I Don't understand what is The Relation between Infinite series and limits [closed]

**I Don't understand what's The Relation or difference between Infinite series and limits **
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### Ratio of Means of two numbers 10 and 100

Table I was reading a book on computer architecture for my exam and came across this table. I understand all the columns except for the ratio of means. How is the ratio of means of 10 and 100 become ...
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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).
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### Equation Involving Ratios

In some of my research, I found multiple equations of this form: $$\frac{ax+b}{cx+d}=k$$ where $a,b,c,d$ are all non-zero integers. Is there a way (that doesn't include factoring or checking within a ...
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### Why does this series diverge using Ratio Test?

So I was working on this problem $$\sum\limits_{n=2}^\infty \frac{2^n}{n^{100}}$$ After all of my work performing the ratio test, I ended up with a $$\frac{2}{n+1} = 0$$ Therefore, I assumed it ...
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### Proportionality of Products

If A is directly proportional to the product of B and C where B and C are not constants, can we always say that A is directly proportional to B and also that A is directly proportional to C?
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### Is any line inside similar triangles is scaled with same similarity ratio like median, height, bisector?

In two similar triangles their median, height, angle bisector and perpendicular bisector (upon middle of a side) are all scaled like perimeters (with same similarity ratio). But can I say so for any ...
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### Does the sign matter for proportionality?

This question arose from Physics, where the force on an object attached on a spring is proportional to the displacement to the equilibrium (that is, the rest position). Also, if the displacement to ...
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### Can one combine proportions like so?

If $$y \propto x$$ and $$y \propto \frac1z$$ does this imply $$y \propto \frac{x}{z}$$ is true? I've tried a few cases and it has worked every time, however I can't find any information on the ...
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### Finding integer coordinates for a pentagon, hexagon, heptagon, octagon, and nonagon, etc.

Wondering what the formula is for finding integer coordinates for an arbitrary "regular" polygon. By regular I mean symmetrical polygons like pentagon, hexagon, etc. In particular, I would like to ...
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### Problem-solving with ratios and similar triangles.

The following question is designed to test problem-solving and reasoning skills with ratios and similar triangles. Without using Pythagoras Theorem or Trigonometry this question is supposed to be ...