Questions tagged [ratio]

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

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2answers
22 views

Mixtures and Replacement

How to approach this question? Let's say we have 40 l of water. Operation 1) 4 l water take out and 4 l juice replaced Operation-2)5 l water taken out and 5 l juice replaced and so on what would be ...
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1answer
24 views

Ratio known and Amount needed known

You have a a recipe for the perfect orange juice, it is: 26 parts Water to 1 Part Orange Juice (26:1). However overall you only want 20ml of mixed liquid (orange juice and water combined). What ...
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1answer
293 views

Ratio and Mensuration of Figures

Is there any quick solution to the problem? Thanks.
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1answer
580 views

What is the probability of an item in a list being chosen if both the list and item have different probabilities?

This is kind of a programming question, but more so a mathematical question. I have two lists that contain various items inside of the lists. Each List has a rate of being chosen, then each item in ...
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0answers
42 views

What function describes the frequency for each unique ratio for all possible expansions n over d where n<d?

I am hoping to solve the following problem for a scientific investigation, which relies on the probabilites of all possible expansions. What function $f(r)$ describes the frequency for each ratio for ...
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1answer
41 views

Solve it using ration [closed]

Box contains 12 items divided in pens and pencils and it costs $20$. If the quantity of pens and pencils are interchanged, the price of the box reduce to $16$. If price per pen is $2$, Find the number ...
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1answer
628 views

what percent of $.72$ quintal is $2.5 kg$?

what percent of $0.72$ quintal is $2.5 kg$? I am a 8 years old boy from INDIA. Please help me. how do I start have no idea. Tomorrow is my exam please help me.
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2answers
60 views

Ratio & Proportion Problem

$\frac{Px}{(b-c)} = \frac{Qy}{(c-a)} = \frac{Rz}{(a-b)}$ Find the value of $(P*a*x) + (Q*b*y) + (R*c*z)$ This question is a problem of my Class VII textbook and no solved examples of the type are ...
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3answers
19k views

How to calculate mixing of two ratios to get desired ratio? [closed]

For the purpose of this example lets say I have two ingredients: water ($100\%$) a chocolate mix ($80\%$ chocolate, $20\%$ water) The goal is to mix them together to create a mix that is exactly $50\...
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2answers
1k views

finding the ratio when two other ratios are given

The ratio of incomes of a and b is 3:4 and ratio of their expenditure is 4:5 . what can be their possible ratio of savings 9:10 or 3:4 or 4:5 or 13:20. I don't find anything suitable in ...
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2answers
53 views

Ratios and percents

Mrs. Smith has 80 birds: geese, hens and ducks. The ratio of geese to hens is 1:3. 60% of the birds are ducks. How many geese does Mrs. Smith have? a) 16 b) 8 c) 12 d) 11 I know that if 60% if ...
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1answer
100 views

How much faster will a task be in percentage terms?

This isn't necessarily a difficult question, but it's something I'm trying to set straight. The task I have in mind is mowing my lawn. Let's say I have a 16" lawnmower. I decide I'd rather have a ...
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1answer
39 views

Need help with ratio calculation

I have 2 objects with the width of: Object 1 = 375 Object 2 = 359 If I change Object 1 width to 333.5, what would object 2 be? This is probably really simple, but I'm trying to get the ...
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1answer
163 views

Incommensurable units as ratios

I am having a bit of trouble understanding the concept of an incommensurable unit. From what I have gathered so far, it is simply a magnitude that cannot be expressed as the ratio of two natural ...
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2answers
1k views

How is a decibel a tenth of a Bel?

By definition, one Bel is log10(P2/P1) (in the power example) and one dB is 10log10(P2/P1), so it appears to me that one dB is ten Bels, not one-tenth of a Bel. Yet, many online publications, ...
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1answer
56 views

Any time saving/ short methods to solve this problem?

Three persons A,B,C whose salaries together amount to $144000. Each spend 80,85 & 75 percent of their salaries respectively . If their savings are in the ratio 8:9:20, then C's salary is? ...
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1answer
700 views

Ratio of two beta random variables

I'm working on a problem for an hour and I wanted to get some hints. Suppose: $y_1, y_2, y_3, y_4 \sim Dir(\alpha_1, \alpha_2, \alpha_3, \alpha_4)$ what is the distribution of $\frac{y_1}{y_1 + y_2}$...
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2answers
575 views

Ratio and percentage related

The ration of boys to girls in a school is 7:6. If the number of boys and girls in the school increases by 10% and 15% respectively in one year, the number of boys will exceed the number of girls by ...
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4answers
36 views

need some help with a power series convergence test problem

Find the interval of convergence for the given power series: $$\sum\limits_{n=1}^\infty \frac{(x - 1)^n }{n(-4)^n}$$ First I applied the generalized ratio test, came out with $\frac{(1-x)}{4}$ ...
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1answer
36 views

Finding the length of a train confusion

Erica noted that a train to Muizenberg took $8$ minutes to pass her. A train in the opposite direction to Cape Town took $12$ minutes to pass her. The trains took $9 $ minutes to pass each other. ...
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2answers
61 views

Eight inches of heavy, wet snow are equivalent to four inches of rain. Estimate the water content in 17 inches of heavy, wet snow.

Eight inches of heavy, wet snow are equivalent to four inches of rain. Estimate the water content in 17 inches of heavy, wet snow. Ok I get 8.4 as the answer for this problem but by calculator I get ...
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3answers
57 views

Algebraic simplification of likelihood ratio

Can someone help me understand how this: $$\frac{f_1(x)}{f_0(x)}=\frac{\frac{1}{\sqrt{2\pi\sigma^2}}\exp\left(-\frac{1}{2}\sum_{i=1}^n(x_i-1)^2\right)}{\frac{1}{\sqrt{2\pi\sigma^2}}\exp\left(-\frac{1}...
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3answers
127 views

If $\frac{a}{b}=\frac{x}{y}$, is $\frac{x-a}{y-b}=\frac{x}{y}$? [closed]

Does this hold? $b,y \neq 0$, $b \neq y$.
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1answer
2k views

Numerical Reasoning EPSO Ratio Question

I would appreciate if anyone can please guide me on the workings to this question from the EPSO site. In 2000, what was the ratio of GDP in the Netherlands to that in Finland? Possible Answers: ...
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1answer
56 views

Mathematical question about currencies

I've tried to get an answer for this question elsewhere but with no luck, so I would appreciate a mathematical analysis of it. Assume $0\%$ commission. Consider three currencies, let's say the Zong, ...
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3answers
91 views

How the red circle marked equations came ?

Yesterday I started to learn algebra with my own. And the first chapter which I'm learning is Ratio . I'm not getting the red circle marked lines in the below image. I tried to understand it but didn'...
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1answer
79 views

How does this line came?

:) Today I started to learn algebra with my own. And the first chapter which I'm learning is Ratio. I'm kind of confuse in an example, in all the lines starting with (*). Until first three lines of ...
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1answer
191 views

Work Out Height Based on Width and Ratio

I'm trying to work out the height of an image. I have this data available to me: width: 320 ratio: 0.66 Is it possible to work out the height based off the data ...
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1answer
392 views

interpreting ratio of two probabilities or should I use a transformation first?

If two 5-year survival probabilities are p1=.55 and p2=.41 the ratio is .55/.41 = 1.34 but since probabilities are in [0, 1] should I take the log first? Which is the more appropriate way to ...
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1answer
80 views

Ratio expectation with dominating denominator

Let $Y$ be a RV taking values in $[0,+\infty)$, and let $X$ be a RV taking values in $[1, +\infty)$, such that $X \ge Y$. Do we have following inequality? $ E[Y/X]≥E[Y]/E[X] $ This question is ...
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1answer
34 views

Simplifying the equation.

I have this equation $$\frac{\left(\frac{x}{a}\right)}{a^n} = \frac{\left(\frac{y}{b}\right)}{b^n} = \frac{\left(\frac{x}{a}+\frac{y}{b}\right)}{a^n + b^n}$$ Just wanted to know how the first two ...
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2answers
1k views

Inverse of ratio

Say I have two equations: $$a = {b \over c} \\ d = {c \over b}$$ Now assume that I know the value of $b \over c$ (e.g. $4$), how would I then determine the value of $c \over b$? Note: I do not ...
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3answers
2k views

Ratio test with limsup vs lim

Could I prove that the ratio test still works using $\limsup(\frac{a_{n+1}}{a_n})$ instead of $\lim(\frac{a_{n+1}}{a_n})$? I think for $\limsup<1$ I could show that for $\epsilon>0, N>1 \...
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2answers
859 views

Ratios of combination

A glass contains vinegar and water in the ratio 1:3. Another glass twice the capacity of the first has vinegar and water in the ratio 1:4. If the contents of both glasses were mixed together in ...
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2answers
545 views

How fast is the water level rising?

A pyramid-shaped vat has square cross-section and stands on its tip. The dimensions at the top are $2\text{ m}\times2\text{ m}$,and the depth is $5\text{ m}$. If water is flowing into the vat at $3\...
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0answers
516 views

Aspect Ratio with two rectangles

This is probably simpler that I'm making it (it would have to be), but I'm stuck and don't even quite know how to language this. Imagine I have two boxes; one has a width of 3/4 of the whole, and the ...
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3answers
124 views

Inverse proportion - Word Problem

Question: given that $B^2$ is inversely proportional to $A+3$ and $B$ is always positive, find the value of $B$ when $A=17$ if $B=5$ when $A=2$. I am so confused on how to work out this question. I ...
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0answers
201 views

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 ...
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2answers
50 views

Efficient way to check whether triangles are similar

If we need to find if a triangle is isosceles, we can compare like a=b, b=c and a=c. But there are 3 comparisons. With $(a-b)(b-c)(a-c) = 0$, we can check it with one comparison. Usually for similar ...
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8answers
14k views

Is there a size of rectangle that retains its ratio when it's folded in half?

A hypothetical (and maybe practical) question has been nagging at me. If you had a piece of paper with dimensions 4 and 3 (4:3), folding it in half along the long side (once) would result in 2 inches ...
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1answer
55 views

Comparing ratios? [closed]

Im 12 and in need help on how to do these comparing stuff. Here is my problem/question So how do I figure this out?
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1answer
18k views

how to work out a total % for 2 components worth 60% and 40%

Trying to work out the overall mark for a module with 2 components eg. component A is worth 40 % of the total and is awarded 55 out of 100 component B is worth 60 % of the total and is awarded 52 out ...
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1answer
92 views

ratio of 3 numbers with a given a number

My sister has a homework but I cannot understand the question correctly (do not know if it is correct as well) 3 numbers are in the ratio of "3:4:5". 28 is the middle number, what are the other 2 ...
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2answers
503 views

Determining the Number of Adult Tickets from a Ratio of 4 is to 5

The ratio of adult tickets to student tickets for the play was 4:5. If the sum of the adult tickets and one half of the student tickets is 260, how many adult tickets were sold? The choices are as ...
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2answers
974 views

Triangle Area Ratio Theorem Problems?

Having a hell of a lot of issues with these problems, supposed to be on the topic of triangle area ratio theorem (ratio area of triangles = ratio of triangles' heights x ratio of triangles' bases.) ...
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1answer
33 views

Calculate profit in investment by a person joined x months later

A and B enter into Partnership investing rs 12000 and 6000 respectively. After 8 months, C Also joins with capital of 15000. The share of c in the profit of 45600 after 2 years will be ? I assume the ...
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1answer
92 views

Ratio can you answer? please help me [closed]

In a mathematics club,there were 8 girls for every 5 boys.When 19 boys and 4 girls were added,the ratio became 9 girls for every 7 boys .How many girls were there at the start.
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1answer
1k views

Solve for minimum x value in two-variable equation provided a ratio

The equation is: $$500 = 5x - 2y$$ I know the ratio of x to y is $7:3$; what is the minimum possible value of x and how would I approach this question?
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0answers
93 views

Is there a difference?

Problem: You have a choice of climbing one of three geometrically shaped mountains. One of the mountains is a perfect cylinder, another is in the shape of a cone, and the third looks like the top half ...
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4answers
74 views

Dividing Numbers Into Rations

The question is: Suppose $60$ is divided into $3$ parts in the ratio of $1$:$3$:$6$. What is the value of the middle part? I tried to take $60$, divide it into $3$ parts and divide those $3$ parts ...