A percentage is a number or ratio expressed as a fraction of $100$. It is often denoted using the percent sign, "$%$", or the abbreviation "$\mathrm{pct}$." -Wikipedia. Percentages are used when describing portions or proportional changes.
Questions tagged [percentages]
1440 questions
3
votes
3 answers
Find the original value without VAT
How to find out the amount without VAT?
$$£\,3.325 + 20\,\% = £\,3.99$$
but, if I do $£3.99 - 20\% = £3.192$ instead of $£3.325$, how can I find out $£3.325$ out of $£3.99$?
Diego Vieira
- 133
3
votes
3 answers
Is there a difference between discount and VAT calculations?
When I remove VAT I divide by 1.x
e.g. VAT @ 20%
£1 /1.2 =£0.83
But if want to remove a % discount do I use the same method as above, or the method below?
20% £1 * 20/100 = £0.20
£1 - £0.20 = £0.80
Scott
- 31
3
votes
1 answer
Percentage expensive or cheaper
I have some prices / costs.
I have an unknown value like 520.
I have a top value that can be 520 or higher.
I have a bottom value that can be 520 or lower.
Let's say the top value us 750 and I want to know how much more in percentage it is in…
Jens Törnell
- 433
2
votes
7 answers
Subtracting 30 percent of which number gives 2000?
Subtracting $30$ percent of which number leads to $2000$?
$$x - (30 \text{ percent of }x) = 2000$$
for example:
$$4000 - (50\text{ percent of }4000) = 2000$$
2
votes
0 answers
Percentage "change factor"
In my math work book there’s a section on, when translated into english, “percentage change factor”. I am looking for the actual name for it in English in order to search more info/help regarding this.
I am not talking about:
change/Original price…
Fridey
- 21
2
votes
3 answers
Complicated Percentage Question
In a certain town some people were affected by a ’flu’ epidemic. In the first
month $20$% of the population contracted the flu whilst $80$% were healthy.
In the following month $20$% of the sick people recovered and $20$% of the
healthy people…
Aspiring Mathlete
- 2,312
2
votes
1 answer
I need help, percentages, ratios, proportions.
A community center is going on a trip to Philadelphia via several buses. The ratio of men to women to children is 1:2:3. If there are 150 people going on the trip, how many men are going? How many women are going? How many children are going?
Can…
2
votes
5 answers
How do you find the minimum percentage who have studied all four subjects?
At college, 70% students studied Maths, 75% students studied English, 85% studied french and 80% studied german. What percentage at least must have studied all 4?
Madhurima
- 21
2
votes
1 answer
Selling apples with out cost price at loss
A vendor loses 4 apple price on selling 36 apples. What is his loss percentage?
I assume answer as 11.11% but answer was 10%. Am I thinking in reverse direction?
Ganesh Vellanki
- 231
2
votes
0 answers
Are these increments in percentages the same? I came to a contradiction while trying to solve this textbook problem
I don't mean to waste your time with this simple thing but I came here because I haven't found a solution. The textbook is Mathematics All Around 5th ed. by Thomas Pirnot. The exercise says: "Assume the board of trustees for your school is bound by…
David Vallejo
- 29
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2
votes
0 answers
Percent contribution between positive and negative number
I need your help
Process 1 + Process 2+ Process 3 = total
Problem 1:
If process 1 value is -900 but the total value is 300
I need to find how many percent contribution of process 1 to the total value?
Problem 2:
If process 1 value is 300 but the…
Manee Chotiros
- 21
- 2
2
votes
1 answer
Explain to 9 year old — Why multiply by 100 and add %, to convert to percent?
My 9 year old child's method
We must convert b in the denominator to 100. Thus we must multiply numerator and denominator by $100/b$, because we can't change $a/b$. Then
$\color{violet}{\dfrac{a}{b}} \equiv \color{violet}{\dfrac{a}{b}} \times…
user53259
2
votes
1 answer
small doubt about Percentage formula
In many places I have seen formula to calculate $x$ % of amount $A$ given as $\frac{x}{100}\times A$.
But I feel writing this way doesn't explains what we are actually computing.
What I have understood by $x$ % of $A$ is first we have to divide $A$…
ogirkar
- 2,681
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- 27
2
votes
2 answers
Intuition behind addition and subtraction of the same percentage resulting in lower final value
Case 1:
Subtracting a percentage $p$ (represented as a number between 0 and 1) from a value $X$ results in the original value becoming $X(1-p)$.
Adding $ p\% $ back to it gives $\{X(1-p)\}*(1+p)$.
Case 2:
Now, adding $p\%$ to $X$ first, we get…
rahs
- 127
2
votes
2 answers
How to find the average compound interest for all years, knowing the starting and ending values, as well as the number of years
For example:
Company X shares in 2016 - 38 USD
5 years later, in 2021 - 66.95 USD
38 + 12% (4.56 USD) + 12% (5.10 USD) + 12% (5.72 USD) + 12% (6.40 USD) + 12% (7.17 USD) = 66.95 USD
What formula should I use to know that the average compound…
Max
- 129