percentage

Zeeshan 01 · 2017-07-17 18:16:20

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

Bob · 2017-07-17 19:03:20

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

Zeeshan 01 · 2017-07-17 21:07:08

Y is 2 time x

Zeeshan 01 · 2017-07-17 21:08:11

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???

Zeeshan 01 · 2017-07-17 23:02:34

Check question 1 I don't understand your formula

Zeeshan 01 · 2017-07-17 23:23:11

X percent is x\100

zetafunc · 2017-07-18 00:05:32

To find of , you'd do:

Similarly, to find of , you'd do:

We're given that that is , so that means

i.e.

Zeeshan 01 wrote:

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???

If you wanted to increase 20 by 10%, one way of doing that is just to do That's because

Bob · 2017-07-18 00:13:59

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

Zeeshan 01 · 2017-07-18 04:01:33

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

Zeeshan 01 · 2017-07-18 04:04:13

Is it true??

Monox D. I-Fly · 2017-07-18 15:36:31

yes

Zeeshan 01 · 2017-07-18 19:17:34

so why ans is 2x

Zeeshan 01 · 2017-07-18 19:27:18

we dont know value of x

Bob · 2017-07-18 19:51:14

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?"

Zeeshan 01 · 2017-07-19 00:15:28

Bob wrote:

I assumed this meant x is 50% of y,

That is not given in my question

Bob · 2017-07-19 19:02:13

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

Bob

Zeeshan 01 · 2017-07-19 23:08:26

So question 1 ans is D? ?

Bob · 2017-07-20 01:08:05

It would appear so.

Bob

Zeeshan 01 · 2017-07-20 02:07:29

Uff!!!

Zeeshan 01 · 2017-07-20 02:08:32

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

Bob · 2017-07-20 03:53:52

Yes. See post 7.

B

sonia100 · 2017-07-20 12:36:40

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".

Bob · 2017-07-20 20:32:56

hi sonia100

Welcome to the forum.

Good explanation!

Bob

Zeeshan 01 · 2017-07-20 21:02:45

Hmm!!!

Zeeshan 01 · 2017-07-20 21:04:32

Bob wrote Yes. See post 7.
B
Means? ?

Math Is Fun Forum

#1 2017-07-17 18:16:20

percentage

#2 2017-07-17 19:03:20

Re: percentage

#3 2017-07-17 21:07:08

Re: percentage

#4 2017-07-17 21:08:11

Re: percentage

#5 2017-07-17 23:02:34

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#6 2017-07-17 23:23:11

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#7 2017-07-18 00:05:32

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#8 2017-07-18 00:13:59

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#9 2017-07-18 04:01:33

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#10 2017-07-18 04:04:13

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#11 2017-07-18 15:36:31

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#12 2017-07-18 19:17:34

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#13 2017-07-18 19:27:18

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#14 2017-07-18 19:51:14

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#15 2017-07-19 00:15:28

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#16 2017-07-19 19:02:13

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#17 2017-07-19 23:08:26

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#18 2017-07-20 01:08:05

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#19 2017-07-20 02:07:29

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#20 2017-07-20 02:08:32

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#21 2017-07-20 03:53:52

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#22 2017-07-20 12:36:40

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#23 2017-07-20 20:32:56

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#24 2017-07-20 21:02:45

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#25 2017-07-20 21:04:32

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