# Tagged Questions

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### simplify $3x^2 \times x^2 + x^3 \times 2x$

Looking at an old assignment, and the function in the title is a derivative result of the product rule, but I've simplified it to $5x^4$, but I have forgotten how I got to that result. Anyone with a ...
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### What percentage is the rest of the black cars in the parking lot

Ok so, Last Monday, a parking lot had 80 cars. Of those 80 cars, 25% were silver. 16 were red, and the rest were black. What percent of the cars were black
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### negative exponent confusion

I am a bit confused with negative exponents so here is an example. Let $4$ to the $-3 = 1\div4\div4\div4$ The thing which confuses me is the $1$, why we use $1$ before dividing. so if i do it ...
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### Postal work math [closed]

If you have 11 pieces and they weigh 6.8 oz. Together What is the individual weight of each piece and ur answer has to be in decimal form of a pound , such as, 0._ _ _ _ lb per piece
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### How to calculate a comparative percentage

We have 1002 seats in Head Start (all full) and 287 waiting for Head Start We have 48 seats in Early Head Start (all full) and 256 waiting for Early Head Start I'm trying to express to the directors ...
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### An equation, where the solution does not exist, but on solving the equation we got a solution. why this is happening?

The solution of the equation $\sqrt{(x+1)} -\sqrt{(x-1)}= \sqrt{(4x-1)}$ is $\frac{5}{4}$,but when we put $x=\frac{5}{4}$ in the given equation, then it does not satisfy the equation. Actually, if ...
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### Average percentage formula

I have something like: Price Quantity Tax (%) 2.2 34 8 1.3 29 7 And so on... After that I get something like: ...
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### Maintain relationship between two numbers, when their sum equals 1

I have a question that I hope won't seem too silly. I have four numbers that add up to one: A= 0.4 B= 0.3 C= 0.15 D= 0.15 Now, assume that numbers C and D are removed and that I want to maintain ...
127 views

### Rationalizing the denominator 3

It is a very difficult question. How can we Rationalizing the denominator? $$\frac{2^{1/2}}{5+3*(4^{1/3})-7*(2^{1/3})}$$
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### Divisibility in base $7$ problem

Find all integers between $0 \leq a \leq 2400$ such they are divisible by $8$ and that their base 7 development has at least $3$ equal digits.
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### Find the brick volume [closed]

So , what's the volume of a brick which its face areas are 72cm²,150 cm² and 300cm². P.S : the brick is a cuboid. Need an answer as soon as possible.
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### Word problem,percentage

Myshko shot at a target. When he hit the target he only hit 5,8 and 10. Myshko hit 8 and 10 the same number of times. He scored 99 points in total, and 25% of his shots missed the target. How many ...
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### solve ratio word problem without algebra

Four gallons of yellow paint plus two gallons of red paint make orange paint. I assume this makes six gallons. So the ratio is 4:2, or 2:1. Question: how many gallons of yellow paint, and how many ...
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### Representing $\frac{3 + \sqrt{5}}{2}$ as a square of a quadratic surd

How can I represent $\frac{3 + \sqrt{5}}{2}$ as square of a quadratic surd? Actually, I was solving a question where $\frac{3 + \sqrt{5}}{2}$ was converted to $(\frac{1+\sqrt{5}}{2})^2$. How did the ...
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### 99 Ninja missions and a single lantern

From http://blog.liveramp.com/2014/01/30/the-case-of-ninety-nine-ninja/: A team of 99 ninja are each sent out on individual missions by their master. Their master tells the ninja that one of them ...
108 views

### Binomial Theorem Practical Problem

I have been studying the 'Binomial Series', Chapter 16, Pg.125 within the Engineering Mathematics Book by John Bird. After completing this section I have attempted to complete the exercises for ...
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### Binomial Theorem - Proving

The viscosity $\eta$ of a liquid is given by; $$\eta = \frac{kr^4}{v*l}$$ Where $k$ is a constant. If there is an error in $r$ of $+2%$, in $v$ of $+4%$ and $l$ of $-3%$, what is the resultant ...
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### Modeling viral growth

I'm trying to forecast the viral growth for a website I'm developing. I've arrived at some monthly growth rates I can expect per month, the difficulty is I'd like to model my growth per week instead. ...
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### The Order of Operations with Brackets

How would one go about answering something like -8-(-2)[4-(-5)]? The problem here really isn't very complicated once one is used to getting down the right ...
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### Need an equation to measure frequency of a certain period over days, months, years.

Example) Curious as to how many times a certain song of 3:46 will repeat over a given amount of time. How many times over a day, month, year, and the remaining growing fraction of time left over.
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### True or false division algorithm problem

Let a,b,c be integers with a not equal to 0 and (b,c)=1. If a divides the product of bc, then a must divide b or a must divide c. My thoughts: I can prove this if (a,b)=1. but I believe it is false ...
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### True or false theory question [closed]

True or false. If a,b,c are integers with a,b not equal to 0, and a divides b and b divides c then a divides c. My thoughts: true
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### How would I solve this algebraically?

So I've got a small question: How do I solve this algebraically? $x^2=x+6$ It's easy to see the answer but how would you solve it algebraically?
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### Average related question

Can some one please let me know how to solve this problem for my son's home work assignment which i am not able to understand. after taking 3 quizzes, your average is 72 out of 100. What must your ...
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### How do you formulate this problem?

IF it takes 12hrs to process 140 claims per month, how many hrs would it take to process 3000 per month?
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### Which decimal can be multiplied by the result of $(x \times 1.15)$ to return $15$% of $x$?

Which decimal can be multiplied by the result of $(x \times 1.15)$ to return $15$% of $x$? For example, when I want to add $15$% sales tax to an item before tax, I would multiply by $1.15$. ...
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### Flies caught by 100 spiders in 100 minutes

I went through the following question: If 5 spiders can catch five flies in five minutes. How many flies can hundred spiders catch in 100 minutes? The answer is calculated by the following ...
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### Why does $10^{k} - 10^{k - 1} = 9 \cdot 10^{k - 1}$

I'm having trouble making sense of this. Again why does: $$10^{k} - 10^{k - 1} = 9 \cdot 10^{k - 1}$$
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### A very simple percentage question or is it?

If $z\% \text{ of }x = y, \text{ given } x,y$ are natural numbers and $50.5\le z \lt 51.5$, then what is the smallest possible value of $x$?
127 views

### could not able to understand Project Euler 18. “Maximum path sum I”

According to question, By starting at the top of the triangle below and moving to adjacent numbers on the row below, the maximum total from top to bottom is 23. ...
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### How many even numbers are there in a set $\{x_1, x_2 … x_n\}$

For example how to calculate how many even numbers are in a set $\{45, 46, 47 ... 456\}$. General question is how to calculate how many even numbers are in a given set of natural numbers which doesn't ...
### Exponent Law Question: $\left(x^2\right)^\frac{1}{2} = |x|$
Quick easy question! I was always taught at school that $(x^m)^n=x^{mn}$. However, I've only just noticed when computing something (two years into an undergrad course..) that for example ...