Questions on basic arithmetic, e.g. addition, subtraction, multiplication, division, powers, radicals, etc.

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0
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2answers
45 views

calculating the total amount compunded anually

I invest 10000$ every month for 15 year I want to know how much money I will get after 15 years if I have 10% interest compounded annually.Any formula to find this.Whats the amount i will receive at ...
2
votes
4answers
409 views

$10+10\times 0$ equals $0$ or $10$

I thought $10+10\times 0$ equals $0$ because: $$10+10 = 20$$ And $$20\times 0 = 0$$ I know about BEDMAS and came up with conclusion it should be $$0$$ not $$10$$ But as per this, answer is $10$, ...
-4
votes
2answers
254 views

partnership calculation

3 partners are doing business No.1 has 60% partnership no2 has 23% partnership no3 has 17% partnership If No2 partner (23% ) want to leave partnership then how many percent partnership ...
4
votes
1answer
589 views

Simplify $\frac{9}{2}(1 + \sqrt 5)\sqrt{10 - 2\sqrt 5} + 9\sqrt{5 + 2\sqrt 5}$

Simplify $\displaystyle{\frac{9}{2}(1 + \sqrt 5)\sqrt{10 - 2\sqrt 5} + 9\sqrt{5 + 2\sqrt 5}}$. I get this when I was doing another Q, but I don't know how to further simplify it. Can anyone help me, ...
0
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3answers
3k views

Time Difference and Arithmetic - Suggestions..

I am currently dealing with problems in which I need to find the difference between different times. One trick that worked for me until now was from here a short summary of which is ...
2
votes
1answer
112 views

Is there a pattern for reducing exponentiation to sigma sums?

The other day I was trying to find a method for cubing numbers similar to one I found for squaring numbers. I found that to find the square of a positive integer n, just sum up the first n odd ...
0
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2answers
79 views

order of operations division

Very dumb question: What is the order of operations in the following: PEMDAS a/b+c = a : b + c (where ":" is the division symbol) 7/1+6 or 7:1+6 in the example below is it 1 or 13?
3
votes
1answer
203 views

Is the arithmetic most mathematicans use a modelled within first or a second order logic?

I often read that arithmetic in first order logic has problems and you really want to do it in second order logic. However, aren't the Zermelo–Fraenkel axioms written down in the language of first ...
0
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3answers
902 views

6/2*(1+2) is 1 or 9? [duplicate]

Possible Duplicate: What is 48÷2(9+3)? Please, look at the picture? Which calculator shows true result and how to prove achieved result?
2
votes
1answer
123 views

Minimum possible value of the largest of $ab$, $1-a-b+ab$, $a+b-2ab$, provided $0\leq a\leq b\leq 1$

The minimum possible value of the largest of $ab$, $1-a-b+ab$, $a+b-2ab$ provided $0\leq a\leq b\leq 1$ is: $1/3,\quad 4/9,\quad 5/9,\quad 1/9,\quad\text{ or }\quad \text{NONE}$ My approach ...
3
votes
3answers
125 views

Find the remainder in the following case.

Find the remainder when $444^{444^{444}}$ is divided by $7$. My approach : $E(7) = 6 $ $444^{444} \pmod 6 = 0$ so , $444^0 \pmod 7 = 1$
3
votes
2answers
145 views

Find the total number of digits in the following case.

Two numbers $2^k$ and $5^p$ are expanded first then written side by side i.e. adjacent to each other. Find the total number of digits in that case if $k = p = 2004$. My approach : ...
4
votes
2answers
173 views

Will the following expression be irrational, rational or integer?

Will the following expression be irrational, rational or integer? $$\sqrt[3]{\sqrt a +b} - \sqrt[3]{\sqrt a -b}$$ where $a$ = $52$ and $b$ = $5$ . By intuition, I think this will be an integer.
6
votes
5answers
167 views

Find the possible value from the following.

Find the possible value from the following. I'm not able to end up on a concrete note, as I'm unable to get the essence of question, still not clear to me. $x$, $y$, $z$ are distinct reals such ...
1
vote
0answers
282 views

square root of s domain transfer function

I have a question about calculating the square root of the magnitude of a transfer function. When you take the square root, what is happening? My initial idea of a magnitude is a single value, but in ...
2
votes
3answers
124 views

Simplifying a fraction

I'm in doubt on how to simplify $ \left (-\dfrac{1}{243} \right )^{-\frac{2}{3}}$. I've started with $\left (-\dfrac{1}{9\sqrt{3}} \right )^{-\frac{2}{3}}$ but now I'm stuck because of this minus ...
1
vote
1answer
132 views

Which theories and concepts exist where one calculates with sets?

Recently I thought about concepts for calculating with sets instead of numbers. There you might have axioms like: For every $a\in\mathbb{R}$ (or $a\in\mathbb{C}$) we identify the term $a$ with ...
0
votes
1answer
90 views

Find the natural number $x$ from this equality. How to solve this type of exercises?

Solve for $x$: $3-\frac{32}{20-\frac{16}{5-\frac{5}{x}} }=1$ When I see exercises like this one I panic because I can't figure out what to do with that variable x. What are the steps in solving an ...
1
vote
2answers
1k views

PEMDAS:How to solve this exercise?

I have the following problem: $$100*\left\{24+100*[1001-4*(25*6+25*4)]\right\}$$ I'm very frustrated that I can't solve exercises like this. I have read about PEMDAS and followed the steps but ...
0
votes
1answer
133 views

How to derive one percentage from two options

I am very bad at mathematics, so apologies in advance. My confusion comes from the voting system on an online poll. Example video (Picked at random): ...
0
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1answer
373 views

How to handle the following percentage scenarios?

I have the following scenarios, but I am unclear on how to handle them correctly. I start off with a value like 200 and the following scenarios are: Remove 10% from 200, and then remove a compound ...
0
votes
1answer
360 views

Finding the number of distinct sub-strings in a binary string.

Whilst solving a question, I have come across a problem regarding the maximal number of possible distinct $k$-length binary sub-strings in an $n$-length binary string. My thought process was that if ...
1
vote
3answers
91 views

Fill in odd combinations in triangle

Can you write a number from 1 to 16 in each of the triangles, using each number exactly once, such that the sum of the two numbers in the two cells that share an edge is always odd? triangle as such: ...
1
vote
1answer
91 views

Puzzle: concatenation is three times product

The numbers A and B have three digits, while C is an odd number with 5 digits. Say you were asked to calculate the integer $(A B) /C$. Instead though you put A and B next to each other to form a ...
2
votes
4answers
792 views

If a number is divisible by a number, is it always divisible by that number's factors?

As the title says, if a number is divisible by a number, is it always divisible by that number's factors? An example being that $100$ is divisible by $20$, it is also divisible by $10, 5, 4, 2$ as ...
3
votes
3answers
297 views

$1 +1$ is $0$ ?​ [duplicate]

Possible Duplicate: -1 is not 1, so where is the mistake? $i^2$ why is it $-1$ when you can show it is $1$? So: $$ \begin{align} 1+1 &= 1 + \sqrt{1} \\ &= 1 + \sqrt{1 ...
4
votes
1answer
111 views

Least value for addition

We know that $$0\leq a \leq b \leq c\leq d\leq e\,\,\text{ and}\,\, a + b + c + d + e = 100$$. What would be the least possible value of $\,\,a + c + e\,\,$ ? I apologize for poor syntax.
2
votes
1answer
269 views

Dividing by 1000 twice?

If I take any whole number and divide by 1000 twice then is it only mathematically possible to have a maximum of 6 numbers right of the decimal point. Example ...
4
votes
1answer
87 views

How do I scale 3 fractions to 3 natural numbers?

Disclaimer: I'm an engineer, not a mathematician I have a set of three fractions (a/b, c/d, e/f). I can multiply them all by another fraction, so that their mutual ratios remain the same. I want to ...
7
votes
3answers
821 views

Building the integers from scratch (and multiplying negative numbers)

Now I understand that what I am about to ask may seem like an incredibly simple question, but I like to try and understand math (especially something as fundamental as this) at the deepest level ...
6
votes
3answers
255 views

Question on some arithmetic calculations

When $6272$ is multiplied by $0.94$ the answer is $5895.68$. When it is divided by $1.06$ the answer is $\approx 5916.9811$. Why is it so? Just as a little background, I am using the default ...
8
votes
5answers
393 views

Arithmetic of irrationals and the Vedanta behind it..

I am really curious about the Vedanta behind the arithmetic operations on irrational numbers. It still got aggrevated after the productive discussions with my friend. So I decided to ask it here. ...
2
votes
2answers
321 views

What are the carried numbers called in an Addition problem

What is the 1 that is carried called? These are all Latin, would this make sense? The Latin word for "carry" is "porto", would it be called Porto? Just guessing here Example: ...
4
votes
1answer
453 views

How to add or multiply decimal numbers?

The tag ''calculus'' may not fit for this question but I couldn't think of anything else. Please feel free to change it. Suppose $a=0,a_{-1}a_{-2}a_{-3}\ldots$ and $b=0,b_{-1}b_{-2}b_{-3}\ldots$ are ...
5
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2answers
323 views

Powers in ASCII text

I have a problem reading a discussion forum post. Namely, in the ASCII text, is 2^3^4 the same as $(2^3)^4$ or $2^{3^4}$?
1
vote
2answers
125 views

bound on recursive series

Let $a_1 = 0$ and $a_i \le \alpha + \beta a_{i-1}$. I am looking for an upper bound on $a_i$ that depends only on $\alpha$ and $\beta$ and $i$. If it helps, $\alpha, \beta \ge 0$.
0
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1answer
2k views

HCF, LCM, and remainders

I think this is kind of a lame problem after seeing the quality of questions on this site, but I couldn't find anything related to my question Now the basic questions is as follows, Q. Find the ...
1
vote
3answers
137 views

Simplified form of $x^{10/3}$

I'm in a intermediate algebra class and am confused about how to get the simplified form of $\sqrt[3]{x^{10}}$ I tend to want to write it as $x^{10/3}$ creating a mixed fraction then simplifying that ...
22
votes
5answers
951 views

a big number that is obviously prime?

I once heard it asserted that $91$ is the smallest composite number that is not obviously composite. The reasoning was that any composite number divisible by $2$, $3$, or $5$ is obviously composite, ...
3
votes
2answers
305 views

Rewriting repeated integer division with multiplication

In many programming languages, such as C and C++, integer division of positive numbers is defined by simply ignoring the remainder. $5 / 2 == 2$. In general, is it true of positive integers $a$, $b$, ...
1
vote
2answers
701 views

How to find the meeting number of two sequences?

How do I find the same number of following two sequences? Will these two sequences ever produce any common number? If no, then what will be the possible near number where they are about to meet? ...
1
vote
1answer
47 views

Mean frequency and period frequency

If I have two frequencies: $f_1 = 20\text{ Hz}$ $f_2 = 40\text{ Hz}$ the mean between them should be $$f_\text{mean} =\frac{20+40}{2}=30\text{ Hz}$$ How come that if I calculate their periods' ...
4
votes
2answers
1k views

Can somebody simply explain Wilson's theorem (for a 13 year old)

I am Rohan Kapur. This is my first time posting on the Mathematics site, although I am quite active on StackOverflow, the programming site. I am doing a Islamic Maths assignment at the moment for ...
10
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3answers
1k views

Is the infinite root of any number equal to $1$?

I was messing around in IRB and I decided to make a $n^{th}$ root function and noticed that for very large roots of numbers, the answer always converges to $1$. It has been a while since I have done ...
1
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0answers
104 views

Collaborative modular exponentiation

EDIT: Rephrased. I have, stored somewhere, the values $a$ , $Q$, $N_1$ (plus its factor) and $a^{2Q} \mod N_1$. I also know $b$, $R$ and $N_2$ (but not its factors). I want to know whether there is ...
4
votes
2answers
766 views

Will Division by Zero be Defined Eventually? [duplicate]

Possible Duplicate: Division by $0$ I've always been inclined to believe that x/0 = NaN is a placeholder for a character or constant that no one has ...
41
votes
12answers
5k views

Is it wrong to tell children that $1/0 =$ NaN is incorrect, and should be $∞$?

I was on the tube and overheard a dad questioning his kids about maths. The children were probably about 11 or 12 years old. After several more mundane questions he asked his daughter what $1/0$ ...
6
votes
4answers
265 views

Multiplication convention rules

Student was asked to convert the following statement into multiplication format $$7+7+7+7+7+7$$ She wrote the answer as $7\times 6=42$ and was marked wrong as the teacher expected $6\times 7=42$. Is ...
1
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3answers
647 views

simplifying formula $\frac{(k-1)(k-1 +1) (2(k-1)+1)}6$

I'm trying to understand my textbook's example (it's part of a mathematical induction problem) and I just don't get how the author managed to simplify this formula: $$\frac{(k-1)(k-1 +1) (2(k-1)+1)}6 ...
0
votes
1answer
2k views

Binary division - find a remainder

I have difficulty in finding the remainder of the next expression: 111010011/1101. What I did: ...