Questions tagged [ratio]

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

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46 views

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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2answers
27 views

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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25 views

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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44 views

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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24 views

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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1answer
19 views

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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31 views

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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1answer
31 views

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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48 views

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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2answers
100 views

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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1answer
16 views

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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190 views

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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39 views

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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1answer
92 views

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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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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20 views

Calculating probabilities from sigmoids

The problem is that I would like a user to rate a genre on a scale from 1 to 100. This input would go into the function as $x and return a number from the sigmoid function. The reason for the sigmoid ...
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12 views

Ratio of project costs to interviewer costs

I am not sure should I add up all the supplier cost but I still can't find the answer. Any ideas
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43 views

what does it mean that plane XY divides the line joining (2,4,5) & (3,5,-4) with a negative ratio

What does it mean that plane $XY$ divides the line joining $(2,4,5) \text{ and } (3,5,-4)$ with a negative ratio? It's an old question I saw when I was in high school. Search results didn't help. I ...
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1answer
50 views

Geometric problem about ratios of line segments: How to transform the limiting case method to a rigorous answer?

In $\triangle ABC$, $D, E, F, G$ are points on the sides of the triangle such that $BD:DE:EC=1:2:3$, $AF:CF=1:1$, and $AG:BG=2:3$. Find the ratio $FH:DH$. My classmate has come up with a brilliant ...
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1answer
12 views

Simple question about averages and proportions/ratios

I'd like to get the global average of 2 numbers in their proportions. How's that possible? Here is the example of what I want: ...
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2answers
46 views

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 ...
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1answer
25 views

Dividing two equations to find a ratio [closed]

The question is: In the moon, the acceleration due to gravity is $1.6 m/s^2$. Calculate the difference in the period (the ratio) of two identical pendulums if one were on Earth and one on the Moon....
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Scaling rectangle and keeping ratio when height and/or width exceed container

I have a 2D box with a Height of 206 and a Width of 202. Inside of this box is a Rectangle. ...
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I want to find a ratio between $\displaystyle T_{2}$ and $\displaystyle T_{1}$

I have the following variables: $$ T_{2}, T_{1}, a_{2}, a_{1}, b_{2}, b_{1}, w, x, y, z$$ These are the following relations that I've found: \begin{align} T_2 &= a_2 + b_2 \\[1ex] T_1 &= ...
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Are my calculations of the pregnancy ratio of the population correct?

So this question is a math question having to do with me calculating the rate of population growth starting from a population of 100,000. I have already gotten the first 3 steps done(sex ratio, ratio ...
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Ratio question help: are my answers correct?

From the question given below, I am trying to, firstly, find the proportion of iPhone users from the information provided in the Business Scenario. Secondly, I am trying to find the share of Android ...
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Relationship between a circle inscribed in a square and a sphere inscribed in a cylinder

The ratio of the area of a circle to the area of the square it is inscribed in is equal to ${\pi\over 4}$ and the ratio of the volume of a sphere to the volume of the cylinder it is inscribed in is $2\...
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1answer
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Equation for Comparing Autos [closed]

I am buying a used vehicle. I want an equation that will allow me to compare two vehicle's value that are identical in every way except price and mileage. For example: Car A: $20395 cost and 83400 ...
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32 views

Currency growth rate (reverse)

For currency audusd: On opening of Day1 the price is 20 and on closing of Day1 the price is 35 So the growth rate is (35-20)/20 = 0.75 So, for usdaud (reverse pair) the price at opening of Day1 ...
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1answer
22 views

Ambigious Word Questions Involving Ratios (Or Do I Not Know The Conventions?)

I am just curious if I was at fault here for the way I answered these questions, or if the book was at fault for not being clear enough. Perhaps I'm missing something regarding the conventions of ...
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29 views

Find ratio of the volume of two cone

Given two sector ABC and PQR, $\angle A=2\theta$, $\angle P=3\theta, AC=2r, PR=3r, $ both sectors are folded into a right circular cone, find the ratio of the volume of two cone. I am having ...
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Finding a unified ratio from two separate ratios

I'm self-studying with Stroud & Booth's amazing Engineering Mathemathics, 7th edition. I'm stuck at a problem set that gives me two ratios of variables A and B, and B and C respectively, an ...
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Turning line around the point but independent of that point

I need to ask you for help. I can't figure it out how to rotate the line around the point which is point of cross with other line BUT at the same time I want my line to be INDEPENDENT of that point. ...
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1answer
28 views

How can I find the ratio of a medium triangle to a smaller triangle?

I know area is $\frac{1}{2} bh$ but I can't use that since there are no numbers. The triangles are isosceles and the medium triangle and the small triangle share a side. How can I find the ratio of ...
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37 views

What is the LCM of a and b if $(a+2 \sqrt{2} )/b$ is the ration of the area of larger circle and smaller circles?

Radius of all four smaller circles is $R$. If the ratio between the area of the larger circle and the sum of areas of the smallest circles is $(a+2 \sqrt{2} )/b$ then find the LCM of $a$ and $b$. ...
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Ratios containing zero

In one of our questions in school, we are asked, For a given index finger length which of the following groups has the longest ring finger if the $2$D:$4$D ratio is: Group A $0.96$, ...
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1answer
71 views

Compare two different prices in stock market

I am trying to develop some algorithm in stock market, I want to compare two different sets of prices, please see below image to understand clearly, If you see above image I have plotted two ...
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1answer
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Calculate adherence using proportion

My task is to calculate adherence of people. If $0$ minutes = $100\%$; $9600$ minutes = $0\%$; what are $480$ minutes equal to?
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Ratios With Three Factors?

How do I compare a different objects with three rates? For instance, if I were to compare the price of apartments I would look at the price per square foot, a rate with two factors. But if I wanted to ...
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1answer
30 views

How is the joint proportionality (joint variation) equation (i.e. $y = kxz$) logically correct?

If $y$ is proportional to $x$, and $y$ is also proportional to $z$, then how are we able to arrive at the equation: $y = kxz$ ? My understanding so far of proportionality, which comes from this ...
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172 views

A is x% more than B

I am taking the AMC10 test, and I don’t want to lose points on silly misunderstandings. When a question says “A is x% greater/less than B”, or things like that sometimes with money, which respect ...
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37 views

Is there an upper bound for the mean of a ratio between two random variables?

Is there an upper bound for the mean of a ratio between two random variables ?
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bounding min-entropy gain in differential privacy

In privacy-related computer science literature, we say that a randomized algorithm $\mathcal{K}$ that produces a model $\theta$ from a sample $X=(x_1,...,x_n)$ is $\epsilon$-differentially private iff ...
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1answer
74 views

Ratio comparing rate of volume of sphere and surface area

Find and express a ratio that compares the rate at which the volume of the sphere changes with respect to the rate at which the surface area of the sphere changes (the ratio will be a function of $r$)....
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34 views

Find a ratio of triangle's height segment

Given a right angle triangle ABC (C = 90) and a median AM. CD is the height of the triangle ...
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29 views

Does convergence by the ratio test for sequences implies that the sequence is monotonic?

I wonder, Let's say $(a_n)_n$ is a sequence. If $ \frac{a_{n+1}}{a_n} \to L $ and $ L<1$. Then $ a_n \to 0 $. But, does it mean that $a_n$ is monotonically decreasing? (For every $n$, $a_n > ...
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1answer
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If one region is above the $x$-axis, and the other below it, should “the ratio of their areas” use absolute value?

Good morning mathematicians, I apologize for asking such a basic question. When you are to find the ratio of "Area 1" and "Area 2", such that "Area 1" is the area of a region above the x-axis and "...
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1answer
28 views

Inequality involving Monotone likelihood ratio and CDF ratio

This problem has really been bothering me and I have no idea whether the statement is true or not. So any help is appreciated. Suppose $f(x)/g(x)$ satisfies monotone likelihood ratio property and ...
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Ratios and rounding figures to nearest thousand

I'm using the WHO Suicide Statistics to try and ascertain the rate of suicide per 100,000 of the population. I'm afraid I'm not from a maths background and this is the first time using Stack ...