Questions on basic arithmetic involving numerical quantities only. Questions involving variable values (other than the result of the operation) should be placed under the (algebra-precalculus) tag.

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-3
votes
0answers
23 views

What is the partitive proportion of the given below?

Here's the given: $a$ is $42.08$%, $b$ is $26.25$% , $c$ is $15.42$% , $d$ is $11.33$% and $e$ is $3.12$%. If that's the case, what's the partitive proportion of $a:b:c:d:e$? I don't know how to get ...
2
votes
2answers
30 views

Length of side of biggest square inscribed in a triangle

I have seen that the length of each side of the biggest square that can be inscribed in a right triangle is half the harmonic mean of the legs of the triangle. I have not seen a rigorous explanation ...
-8
votes
1answer
110 views

is all math beyond arithmetic just advanced arithmetic? [on hold]

Is it true that at the bare-bones of all advanced math, its all just mostly arithmetic? In computer programming languages they are mostly constrained to arithmetic operators. I suppose this is ...
4
votes
4answers
158 views

Converting repeating decimal in base b to a fraction the same base

The repeating decimal .36666... in base 8 can be written in a fraction in base 8. I understand simple patterns such as 1/9 in base 10 is .1111.... so 1/7 in base 8 is .1111. But I'm not too sure how ...
0
votes
1answer
20 views

n is a positive integer and why squares of positive integers is a multiple of 4

When n is an positive integer , 2n is an even number , and the next even number is 2n+2, Hence explain why the squares of the 2 consequtive even numbers is always a multiple of 4, Can I get a hint ...
0
votes
1answer
11 views

Percentage of a collection doubly grouped

Suppose I have a collection of people. I look at one specific group which contains 8% of total people. I know in that group the average percentage of total sweets each person has is 3%. I want to ...
5
votes
4answers
151 views

Are there any natural proofs of irrationality using the decimal characterization?

Mathematicians typically define rational number to mean quotient of two integers. It is not hard to show that a number is rational by that definition if and only if its decimal expansion terminates ...
0
votes
5answers
50 views

Prove that $mn < 0 \iff m > 0$ and $n < 0$ or $m <0$ and $n > 0$.

Prove that $mn < 0$ if and only if $m > 0$ and $n < 0$ or $m < 0$ and $n > 0$. $m,n$ element of integers Just starting out teaching myself discrete math still really bad at proofs, ...
0
votes
2answers
32 views

How do I add chart points together? [closed]

In this video, two points on a chart are added together. As each individual point has X and Y values, how is addition performed? I've researched 'adding chart points' and variations thereof but not ...
1
vote
0answers
16 views

Arithmetic-definability of geometrically-defined arithmetic concepts

Arithmetic-definability of geometrically-defined arithmetic concepts For purposes of discussion take arithmetic to be the study of the [ positive real] numbers, sequences of numbers, etc. and take ...
-3
votes
0answers
48 views

Are a cirlcle and a triangle limited to seven or do they have their own pattern? [closed]

there are 7 triangles in which the perimeter and the measurement of angles are: $5+5+1=11$ $5+5+2=12$ $5+5+3=13$ $5+5+4=14$ $5+5+5=15$ $5+5+6=16$ $5+5+7=17$ The sequence of seven angles of ...
1
vote
5answers
116 views

Any real number has at most two decimal representations [closed]

Here, Tao says that any real number has at most two decimal representations. Is this really true? I always thought $\pi$ has only one decimal representation.
5
votes
2answers
195 views

⋇ “Division Times” operator in Unicode (U+22C7)? [duplicate]

I found this maths operator in Unicode: ⋇ It is called "Division Times" (U+22C7). Does it behave like ±? For example: 3 ± 2 means it is an ∈ {1, 5}. So 3 ⋇ 2 means it is an ∈ {1.5, 6}?
0
votes
0answers
18 views

Limit problems involving number series

One of the limit problem I study about arithmetic sequence before but i don't really understand about how the sequence of "n" or "x^n" which in some problem, the answer which "n" will change to (n-1)...
1
vote
0answers
23 views

Algorithm that calculates decimal places of number

My background. I am a school student. Recently, we learned about rational numbers and irrational numbers. For example, we were told that rational numbers can always be written as a repeating decimal, ...
3
votes
0answers
62 views

Algebraic number that exponentiated with algebraic number give $\pi$

I'm not sure if an algebraic number elevated with an algebraic exponent can give rise to a transcendental number. If that's the case does anybody know a closed form for an algebraic number that ...
0
votes
1answer
29 views

Is there a general algorithm for these “simple” arithmetic problems?!

Find a number with two digits such that when it is divided with the number itself in reverse order it gives the value 1 and remainder 9, while when it is divided by the sum of its digits it gives 5 ...
1
vote
0answers
24 views

Have I applied this function to a number properly?

There is a bounded, continuous, even function of a variable t that satisfies the functional equations $$f(t)+f\bigg(t+\frac{1}{2}\bigg)=0$$ and $$2f\bigg(\frac{t}{4}\bigg)+f\bigg(t+\frac{1}{8}\bigg)=1$...
-2
votes
1answer
48 views

Is it proper to say that zero divided by an integer $x$ has a remainder of $x$?

Is, for instance, $$\frac{0}{3} = 0$$ with a remainder of $3$? Thank you (:
0
votes
3answers
45 views

The second term of an arithmetic sequence is $13$ and $5^{th}$ term is $31$. What is the $17^{th}$ term of the sequence?

$4.$ Evaluate the following: $a.$ The second term of an arithmetic sequence is $13$ and $5^{th}$ term is $31$. What is the $17^{th}$ term of the sequence? I am trying to do this question (see ...
4
votes
1answer
35 views

A simple question about the Hamming weight of a square

Let we define the Hamming weight $H(n)$ of $n\in\mathbb{N}^*$ as the number of $1$s in the binary representation of $n$. Two questions: Is it possible that $H(n^2)<H(n)$ ? If so, is there ...
2
votes
0answers
25 views

Can you check if my final answer correct? (Compound interest problem)

Problem: Blooie has the following obligations: 100,000 due after 4 years without interest and 200,000 dues after 3 years with accumulated interest at ($j_1$ = 0.12, $m_1$ = 2). Blooie wants to ...
1
vote
1answer
22 views

Answer to this compound interest problem?

Can anybody help me with this problem? When will a payment of 300,000 galleons cancel Mr. Weasley’s liabilities to Gringott’s Bank of 100,000 galleons due after 2 years and 150,000 galleons ...
5
votes
4answers
135 views

Prove that $10^{340} < \dfrac{5^{496}}{1985}$

Prove that $10^{340} < \dfrac{5^{496}}{1985}$. I said since $2^{13} < 10^{4}$, we see that $5 = \dfrac{10}{2} > 10^{\frac{9}{13}}$ and so $10^{340} < \dfrac{10^{343.38}}{1985} <\dfrac{...
1
vote
1answer
18 views

Short-cut for computing some large number N (mod 3)

Is it OK to assert that a number (mod 3) is the sum of each of its digit (mod 3), i.e., for an n-digit number represented by a1a2a3...an (mod 3) = a1 (mod 3) + a2 (mod 3) + a3 (mod 3) + ... + an( mod ...
0
votes
1answer
32 views

Relative speed of minute hand in a clock

In a 12 hours clock: The minute hand has to chase the hour hand with a relative speed of 5.5 degrees/min what is the mathematical derivation of this relative ...
-4
votes
1answer
48 views

Buy Get Offer Calculation?

I have some clarification regarding any equation to do some logic like Buy 2 Get 3 Offer with repeat (means if i buy 4 then 6 to be off) If i add 2 quantities of product to cart then another 3 ...
0
votes
2answers
14 views

Making $r$ the subject of a formula

Making r the subject $ S = 2xr^2 + xrl $ On the right side of the equation , I factorise $r$- $ r ( 2xr + xl ) $ I realised that I still have a $r$ inside $2xr$ . How do I remove that $r$ ? ...
4
votes
3answers
255 views

The Google calculator says that $\left(\frac00\right)^0=1$. Is this true?

According to Google, $\left(\frac00\right)^0=1$. Is this true? Why or why not?
2
votes
0answers
28 views

What is the name of the typography symbol for the line under which totals/solutions are written?

I've tried googling for this, but no keywords I can come up with provide meaningful results. Specifically, the line used in basic arithmetic for addition, subtraction, and multiplication. Does this ...
-2
votes
1answer
24 views

How many k-ary functions are there for n-valued logic? And what are the formal language implications?

I believe the answer is n^n^k for any values n and k, where k=the number of arguments and n=the number of possible values that may be taken on. I just want to verify this, since I haven't been able to ...
25
votes
3answers
4k views

What is this operator called?

If $x \cdot 2 = x + x$ and $x \cdot 3 = x + x + x$ and $x^2 = x \cdot x$ and $x^3 = x \cdot x \cdot x$ Is there an operator $\oplus$ such that: $x \oplus 2 = x^x$ and $x \oplus 3 = {x^{x^x}}$? ...
-3
votes
1answer
30 views

Here is a break-down graph of operations done in 4-bit integer multiplication.

The blue nodes represent the number $b = b_3b_2b_1b_0$, and the green nodes represent the number $a = a_3a_2a_1a_0$. The yellow nodes are the output bits after multiplying $a \cdot b$. If $a\cdot b$ ...
6
votes
1answer
177 views

Addition, subtraction, multiplication and division of irrational numbers, correct to $n$ decimal places

Suppose we want to do one of the four basic arithmetic operations on two irrational numbers, and we want some confidence that our answer is correct to $n$ significant figures/decimal places. Doing ...
2
votes
5answers
138 views

What is the actual meaning of power which is less than 1? [duplicate]

$3^4 = 3 \cdot 3 \cdot 3 \cdot 3$ $3^2 = 3 \cdot 3$ $3^1 = 3$ But my problem is for below 1: Example: $3^{0.7} = \ ?$ Can you please explain it to clear my doubt?
0
votes
1answer
20 views

what are the formal names of operands of unary operations?

In case of binary operations, operands have formal names. Taking addition for example: $$a + b$$ We can formally call $a$ the augend and $b$ the addend. Names for operands are available in individual ...
8
votes
5answers
637 views

Is a negative number squared negative? [duplicate]

$-3^2 = -9$ I found this problem while doing an algebra refresher in the book The Complete Idiot's Guide to Algebra. I asked my engineer brother this problem and he got it wrong. A search on Google ...
0
votes
0answers
33 views

How to solve this Algerbraic expression? and what is the proper name for this problem

I am studying for a teacher exam and I am stumped with this problem $3\cdot \frac{(2+6)^2}{6}$ I know that the answer is $32$ because of the answer sheet, but how and why is this the answer. Can I ...
1
vote
4answers
361 views

How does 5.9-7.66=-1.76? [closed]

Sorry for such an easy question but this has been confusing me like crazy. I have borrowed like normal and subtracted like every other problem, and the answer I get is -2.24. How is this wrong?
0
votes
2answers
58 views

Working out how thick a stack of 80GB of printed A4 papers will be

I been going through some of my math unit workbook for Computer Science and im stuck on a question which is phrased: "Given that a single page of A4 paper can display 50 rows by 60 columns of 12pt ...
2
votes
1answer
20 views

Spending and left over amount/percentages

Question 1) Cam would like to spend some of his money on friends. Of the 350 dollar budget he was given, he has to spend 75.00 dollars on office supplies, 10.00 dollars per person for an entrance fee ...
8
votes
2answers
234 views

I derived a new formula related to arithmetic sequences, I think!

First of all, I am a 12th grader so I don't know how to write research notes. So please forgive me if my writing is not so impressive! I don't know what to do to tell the world about whatever I found....
5
votes
4answers
46 views

How many applicants need to apply in order to meet the hiring target?

Cam needs to hire $30$ new employees. Ten percent $(10\%)$ of applicants do not meet the basic business requirements for the job, $12\%$ of the remaining applicants do not pass the pre-screening ...
0
votes
0answers
33 views

Percent Problem with different answers

We have 81% of our team here today and we have 16 team members. How many members are missing today? A) 2 B) 3 C) 4 D) 12 E) 13 My answer: I did $(0.81)(16) = 12.96$ Rounding up that would give us E)...
62
votes
7answers
5k views

Why does the symbol for the multiplication operation change shape?

Why does the "$\times$" used in arithmetic change to a "$\cdot$" as we progress through education? The symbol seems to only be ambiguous because of the variable $x$; however, we wouldn't have chosen ...
0
votes
1answer
15 views

Convert currency base from one base to another

Consider a list of currency rates where the base is USD: 1 USD = 0.90390 EUR 0.74771 GBP 1.30101 CAD how can I convert the base from USD to GBP, such that I ...
-1
votes
1answer
14 views

Ratios question [closed]

Two water taps , One big , one small , are used to fill a rank of capacity 4 $m^3$ with water . Small water tap supplies water to the tank at a rate of p $m^3$ per min and the big water tap supplies ...
4
votes
2answers
55 views

Maximizing product of five-digits numbers

From a French 2016 puzzle and math contest, where no calculator is allowed Using each of the digits $0,1,2,3,4,5,6,7,8,9$ exactly once, find two five-digit integers such that their product is ...
0
votes
1answer
39 views

Finding the sum of numbers between any two given numbers

I tried to derive this type of formula and ended up with this . But it's not holding true for all the numbers. Can you please tell what I've done wrong !!
0
votes
2answers
35 views

Why shift the result of subtracting vectors?

Why do we shift the resulting vector after subtracting any two vectors a and b? I learned that when you add any two vectors a and b, the sum vector looks like the one that can be seen in the picture ...