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Questions tagged [arithmetic]

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. Questions about number theory (sometimes called "arithmetic") should not use this tag and should instead use (number-theory) or (elementary-number-theory).

Arithmetic is defined as operations upon numbers using $4$ main operations along with many others:

addition - the sum of two numbers

subtraction - the difference of two numbers also defined as the addition of negative numbers

multiplication - the area of a rectangle with sides of lengths equal to the two operands

division - the number of times one number can be subtracted from another before equaling zero. Sometimes it will allow decimals and in other cases there will be a remainder left over when a number doesn't go into another evenly

See Arithmetic.

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A shopkeeper sells a T-shirt at a profit...

A shopkeeper sells a T shirt at a profit of $16$%. Had he bought it at $4$% less and sold it at Rs $12$ more, he would have made a profit of $25$%. Find the cost price of T-shirt. My Approach: Let the cost Price of T-shirt be…
pi-π
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Proportional Equation with Variable in Denominator

Middleschool mather here. When solving for p in the proportion equation below our teacher tells us to handle the variable in the denominator first -- as if order of rationalization matters here: $$\frac{8}9 = \frac{12}p$$ School Solution First…
LogBar
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Order of operation confusion

I need to state I am no mathematician, which, by light of the question I'm about to ask should be evident. A friend of mine recently asked a group of us what we thought the answer to this simple problem is. 6 - 6 * 0 + 6 / 6 A bunch of us gave the…
David Barker
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Linear relation of prices

If 100 units have a unit cost of $18 and 500 units have a unit cost of $15.5, what is the cost of 2000 units? I was asked this in an interview and the only thing I could think of was for a 5 multiple of units cost goes down by $2.5 so for 20…
srip
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If $T_n = n(n+2)$ for a given sequence, verify that the sequence is not arithmetic.

If $T_n = n(n+2)$ for a given sequence, verify that the sequence is not arithmetic. I can't figure out how to substitute $T_{n+1}$ for $n$ correctly and work out the brackets afterwards in a good order.
Alpha
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Confusion about order of operations

The question is simple, why the following is wrong!? 24 $\div$ $\frac{9}{-3}$ = 24 $\div$ 9 $\div$ -3
Klaus82
  • 139
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Numeration a numeral with 2 variables

could you help me ? If $a,b,c$ in $\mathbb{N}$ such that $(\overline{ab})^{3}=\overline{1c8ab}$ then the value of $2b-a-c$ is ? Thanks!
Franzz
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How do you simplify fractions that have exponents?

I'm not sure how to simplify a fraction with a large exponent for example: $$\frac{2^{2001} \cdot 3^{2003}}{6^{2002}}$$
T.K.
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Calculating a ratio from a ratio pattern

I am having difficulty with the following problem A computer chip manufacturer expects the ratio of number of defective chips to the number of chips in all future shipments to equal corresponding ratio for shipments S1,S2,S3 and S4 combined as…
MistyD
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why do I need to specify a negative when summing to a negative number?

The context: $4 - 4 = 0$ Ok, the first number is assumed as a positive and the operation here is a subtraction, so the second number is a positive also. So I can summ it in the same way by specifying the second number as a negative: $4 + (-4) =…
jackJoe
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Find the nth multiplication of a number

How do I directly find the $n$th multiplication by $2$ of a number, $x$? $$ f(x) \implies S_x \mid x_n \in S_x \implies n = 1 \lor x_n = x_{n-1}\times 2 \mid n \in \mathbb{N} $$ Examples: $$ f(1) = 2^{n-1} \implies S_1 = \{1, 2, 4, 8, ...\} \\ f(2)…
user193661
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problem solving involving time

This a summary of the question (because it was really long) Everyday A leaves home before 5pm to pick B up from the train station at 5pm and drive home One day B catches an earlier train that arrives at the station at 4pm. B decides to walk home…
kjhg
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Finding constant speed

Lets say someone is flying at constant speed from place $X$ to place $Y$ and back. Going to X takes 5 hours (with the wind) and coming back from X to Y takes 6 hours. Lets assume that the wind is at a constant speed, then how long would it take for…
fosho
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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 on the method how to solve this ? Thanks !
user307640
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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 and remainder 11. My attempt: Write this number as…
Maxtron Moon
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