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**percentage**

**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

Q1. If x percent of y is 50 then what is y

a. 2x

b. 50x

c. x

d. NOne

Q2... in july,the prize of sugar increased by 10% , in August,it is declined by 20% and in september,it is increased by 10%,What is final Decline in prize

a.3.2%

b.Zero

3.20%

c...None

MZk

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,208

hi Zeeshan 01

Q1. Solve this for y:

Q2. The best way to solve this is to change the percents into 'multipliers'

eg . An increase of 10% is the same as multiplying the original by 1.1

and a decrease of 20% is the same as multiplying by 0.8

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

Y is 2 time x

MZk

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

eg . An increase of 10% is the same as multiplying the original by 1.1

and a decrease of 20% is the same as multiplying by 0.8

Means???

MZk

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

Check question 1 I don't understand your formula

MZk

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

X percent is x\100

MZk

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To find of , you'd do:Similarly, to find of , you'd do:We're given that that is , so that meansi.e.

Zeeshan 01 wrote:

If you wanted to increase 20 by 10%, one way of doing that is just to do That's because
eg . An increase of 10% is the same as multiplying the original by 1.1

and a decrease of 20% is the same as multiplying by 0.8

Means???

**LearnMathsFree: Videos on various topics.New: Integration Problem | Adding FractionsPopular: Continued Fractions | Metric Spaces | Duality**

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,208

Zeeshan 01 wrote:

Y is 2 time x

Correct!

Multipliers

example. Increase $20 by 15%

so

The last calculation here is the quickest way to get the new value.

To write a multiplier

(1) Write the % as a decimal (0.15)

(2) Add 1 (1.15)

If there is a percentage decrease:

example. Decrease $20 by 15%

so

To write the multiplier for a decrease

(1) Write the % as a decimal (0.15)

(2) Subtract from 1 (0.85)

If there are 3 percentages changes:

(1) Work out the 3 multipliers and times them together (M = M1 x M2 x M3)

(2) Convert back to a single % (M-1)/100

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

He is saying that y =5000\x????

MZk

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

Is it true??

MZk

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**Monox D. I-Fly****Member**- Registered: 2015-12-02
- Posts: 981

yes

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

so why ans is 2x

MZk

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

we dont know value of x

MZk

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,208

If x percent of y is 50

I think the confusion is because of the wording here. I assumed this meant x is 50% of y, which leads to y = 2x as an answer.

zetafunc assumed this meant x% of y is 50., which leads to his answer. That is a correct interpretation of what is written, but this wording is not how a person brought up on maths In England would phrase the question **. I noticed the multi-choice possibilities and decided to interpret the wording accordingly.

On a world-wide forum, where most posters communicate in English, this is going to happen occasionally. We all just have to be aware of the difficulty and make allowances.

Bob

** If I was setting this as a question I would write "x is a fraction of y. When written as a percentage, it is 50%. What is y in terms of x?"

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

Bob wrote:

I assumed this meant x is 50% of y,

That is not given in my question

MZk

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,208

Ok. In that case zetafunc's answer is correct.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

So question 1 ans is D? ?

MZk

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,208

It would appear so.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

Uff!!!

MZk

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

If we know x then the value of y is determined!!!! In question 1

MZk

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,208

Yes. See post 7.

B

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**sonia100****Member**- Registered: 2017-07-20
- Posts: 2

Q2... in july,the prize of sugar increased by 10% , in August,it is declined by 20% and in september,it is increased by 10%,What is final Decline in prize

a.3.2%

b.Zero

3.20%

c...None

The answer is "a"

Explanation:

First let's assume this is the price for a 30 pound bag of sugar, which we will just call a bag.

Say the price of a bag, in June was $100.00. Come July and the price goes up 10%. Ten percent of 100.00 means 10 per 100; or ten out of every hundred things. Ten cents out of one hundred cents, is 10 cents out of a dollar so 10 cents is ten per cent of a dollar. Just like ten dollars are ten percent of a one hundred dollars bill.

So you add 10% of $100.00, to $100.00 you get ...

$100.00 + $10.00 = $110.00

$110.00 becomes the new price for the same bag of sugar, after the July increase.

To obtain the new price, you need to find out what 10% of the price is.

remember 10 cents = 10% of a dollar, if you look at the display at the store, there is a decimal point, and after the decimal point the cents are shown. 10 cents are shown as $ .10

To get 10% of any number, just multiply the number times 0.10

To get 20% of any number, just multiply the number times 0.20

To get 25% of any number, just multiply the number times 0.25

To obtain the new price you multiplied 100 x 10% = 10.00. Then added the result to the $100.00

But in August, the price goes down by 20%. That is 20 cents out of every dollar. So now you have to deduct, which means subtract, 20%f of the new price. If your bag during July sold for $110.00, after the August decrease, the same bag, will sell for 20% less.

Lets find 20% of $110.00 by multiplying $110.00 times 0.20

110.00 x .20 = 22.00

So the new price in August is:

$110.00 - $22.00 = $88.00 price after the August reduction in price.

Come September, an increase of 10% of $88.00.

$ 88.00 x 0,10 = $8.80

So the new price is:

$ 88.00 + $8.80 = $96.80

With this information we can answer the question:

If sugar was $100.00 a bag before any of this, and sugar is now $96.80 per bag,

The price definitely declined, but, by what percentage?

$100.00 - $96.80 = $3.20

if it was $100.00 a bag, and it declined by $3.20 per bag

the decline is 3.2 dollars out of 100 dollars which is answer "a".

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,208

hi sonia100

Welcome to the forum.

Good explanation!

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

Hmm!!!

MZk

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 648

Bob wrote Yes. See post 7.

B

Means? ?

MZk

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