Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**mandy jane****Member**- Registered: 2010-09-23
- Posts: 1,003

Hi I will work on this question and get the answer back to you tomorrow ok

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

Okay I agree let us leave it a day.

EDIT:

Answer to Q3 for the record: 212.62125/500 = 0.4252425

Multiply by 100 to convert to a percentage: 42.52425% which rounds to 43%

Since Q4 is slightly easier than Q3 and similar you might like to attempt Q4.

I will leave it up to you. Take your time and try to get the answer correct.

*Last edited by SteveB (2014-07-26 08:11:25)*

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

Mandy. Are you okay? Are you still continuing this?

Perhaps continue on Monday?

EDIT:

Consider a series of Os and Xs:

OOOOOOOOOO

OOOOOOOOOO

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

Each row has 10 of the letter. Two fifths of these are Os and three fifths are Xs.

Imagine that there were two lots of that ie:

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

Out of 100 there are 40 Os and 60 Xs. So as a percentage there are 40% Os and 60% Xs.

You could do 2/5 = 0.40 then x 100 -> 40 %

and then 3/5 = 0.6 then x 100 -> 60 %

Now try answering Q4 with that method and round the answer off.

Okay I will reveal the answer to Q4:

I am getting: 9/29 = 0.31034... = 31.034...%

Rounded to the nearest percentage 31%

I am getting 7.5 / 29 = 0.258620..... = 26% rounded to the nearest percentage.

I will go through the other questions for completeness....

I apologise in advance if there are any mistakes.

The rate part of the question involves a cost of £3 per cubic metre and 120 cubic metres used.

So we do: £3 x 120 = £360

The standing charge added on is £100 regardless of other costs so:

£360 + £100 = £460

Then an allowance for VAT at 20% has to be made so:

£460 x 1.20 = £552

First observe that 13000 kWh has been used and divide by 1000.

This is because the rate is 47.50 per 1000 kWh.

So we do £47.50 x 13000 / 1000 = £617.50

Then add the yearly standing charge of 150:

£617.50 + £150 = £767.50

Then add 20% VAT:

£767.50 x 1.2 = £921

I am getting (37 x £7) + ( 2 x £9 ) = £277

I am getting £259 x 4 = £1036

£277 x 48 = £13296 for the amount excluding holiday pay

£13296 + £1036 = £14332

£4332 is taxable

£4332 x 0.2 = £866.40

*Last edited by SteveB (2014-07-29 02:07:42)*

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

Let's revise percentages. Don't worry about those above questions Mandy.

Here are a few examples of O and X percentages where the number of letters rather than the area is of concern.

Since the letters have different widths I will stick to the same length of row in each case in terms of the letters.

This is a case of 10% Xs and 90% O

XXXXXXXXXX

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

Of course since percentages are a measure of proportion there don't have to be 100 items as such:

X

OOOOOOOOO

If you have the above situation then there are 9 Os and 1X there so the proportion of Xs is still 10%

and the proportion of Os is still 90%

If you have this:

OO

XX

The proportions are 50% X and 50% O

You could expand this to:

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

So there are 5 lots of ten of each. So there are 50 Os and 50 Xs meaning 50% O and 50% X.

I will leave it there for now. You have some reading to catch up on. I will leave you to it.

One question for you to try:

What are the percentages in this case:

OOO

XXX

XXX

XXX

What percentage of those are Os ? What percentage of those are Xs ?

EDIT: Another hint:

OOOOOOOOOO

OOOOOOOOOO

OOOOOXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

*Last edited by SteveB (2014-07-29 07:04:55)*

Offline

**mandy jane****Member**- Registered: 2010-09-23
- Posts: 1,003

Hi 3% are 0 and 9% are X am I right send me a message back please

Offline

That is not correct.

Hint: try to express it as a fraction first

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'Humanity is still kept intact. It remains within.' -Alokananda

Offline

**mandy jane****Member**- Registered: 2010-09-23
- Posts: 1,003

Hi mandy here if it is a fraction would it be 3/9 then am I right send me a message back please

*Last edited by mandy jane (2014-07-28 06:45:02)*

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

3% and 9% cannot be correct because the total of these two percentages is 12% and the two should add up to a whole namely 100%.

You could try expressing it as a fraction first that would be my method as well.

*Last edited by SteveB (2014-07-29 02:12:36)*

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

You are getting warmer but that still does not work.

The total of all of them is 12 so the thing on the lower part of the fraction has to be the amount that it is out of.

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

The answer obtained by 3/9 would be 33.333.... % which is not right.

The denominator (bottom of the fraction) is the whole of them.

The numerator (top of fraction) is the "partial bit" of the proportion in each case.

Try again ?

Reminder of the question:

Let us call this Question (1):

What are the percentages in this case:

OOO

XXX

XXX

XXX

What percentage of those are Os ? What percentage of those are Xs ?

ANSWER: 25% are Os and 75% are Xs.

I was wanting to see something like this:

total number of items = 12

3/12 = 0.25

9/12 = 0.75

0.25 = 25%

0.75 = 75%

EDIT: Please refer back to post number #1429 at the end of the post.

Another question:

Let us call this Question (2):

What percentage of these are Xs ?

XXXXXXXXXX

XXXXXXXXXX

XXXXXXXXXX

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

Each row has exactly ten items in and the total is 100.

ANSWER:

Since the total is already 100 by inspection 30% are Xs and 70% are Os

Here are four questions on percentages for you:

Question (1)

Using 100 symbols in total which are either Xs or Os represent the percentage 40% Xs and 60% Os

Question (2)

What are the percentages of Xs and Os in this diagram?

XXXXXXXXXX

XXXXXXXXXX

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

OOOOOOOOOO

Question (3)

Using only 4 symbols in total represent 25% Xs and 75% Os

Question (4)

What percentages of Xs and Os are represented by this diagram?

XX

OO

*Last edited by SteveB (2014-08-06 00:02:36)*

Offline

**mandy jane****Member**- Registered: 2010-09-23
- Posts: 1,003

Hi Steven or any one else

Question 1 using 100 symbols in total which are either Xs or Os represent the percentage 40% Xs and 60% Os

0000000000

0000000000 =40% are Os

0000000000

0000000000

Xx xx xx xx xx

Xx xx xx xx xx

Xx xx xx xx xx 60% are Xs

Xx xx xx xx xx

Xx xx xx xx xx

Xx xx xx xx xx

Question 2 what are the percentage of Xs and Os in this diagram

xx xx xx xx xx

Xx xx xx xx xx

0000000000

0000000000

0000000000

0000000000

0000000000

0000000000

0000000000

0000000000

20% are Xs

80% are Os

Question 3 using only 4 symbols in total represent 25% Xs and 75% Os

Need help with this one please?

Question 4 what percentage of Xs and Os are represented by this diagram

Xx

00

2% are Xs

2% are Os

Am I right can anyone let me know please?

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,481

There are 2 X's and 2 O's that means out of 4 symbols 2 are X, so 2 / 4 = 1 / 2 which is 50%

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

Offline

**mandy jane****Member**- Registered: 2010-09-23
- Posts: 1,003

Hi bobbym mandy here do you know the any of the answers to any of the other questions or not? Send me a message please

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,481

Hi; I gave you that hint because you are asking but I would rather not interfere with what Steve is doing with you. pappym used to say, "too many cooks spoil the broth," meaning that too many people trying to help, each with different styles will only confuse you. That would not be good.

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

Let us have a look at question 4 and think about it in a different way:

We had 4 symbols in total namely:

XX

OO

Now let us imagine that we repeat those four items until there are 100 symbols:

XXOO XXOO XX

OO XXOO XXOO

XXOO XXOO XX

OO XXOO XXOO

XXOO XXOO XX

OO XXOO XXOO

XXOO XXOO XX

OO XXOO XXOO

XX OOXX OOXX

OO XXOO XXOO

There are 100 symbols altogether.

There are 25 pairs of Xs so there are 50 Xs.

There are 25 pairs of Os so there are 50 Os.

I conclude that 50% are Xs and 50% are Os.

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

Question 3 was probably the most tricky for you,

but if you think about it if you have

"Using only 4 symbols in total represent 25% Xs and 75% Os"

then we want to end up with 4 symbols in total.

So what is 25% of 4 items? Well the answer is 0.25 x 4 = 1

So we have only 1 X

Now what is 75% of 4 items? Well the answer is 0.75 x 4 = 3

So we have only 3 Os

So the answer is XOOO

*Last edited by SteveB (2014-08-06 22:01:44)*

Offline

**mandy jane****Member**- Registered: 2010-09-23
- Posts: 1,003

Hi Steve mandy here was I right with the other questions or not? Can you let me know please?

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

I am going to class questions 1 and 2 as correct with full marks.

With question 3 you did not manage to end up with a representation so no marks for that I'm afraid.

With question 4 you would only be right if there were another 96 symbols knocking about somewhere so I will class that as a good effort, but wrong.

So 2 out of 4 correct.

Offline

**mandy jane****Member**- Registered: 2010-09-23
- Posts: 1,003

Hi Steve is that good or not? Let me know please?

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

I think that you have made a good effort with your answer especially questions 1 and 2, but maybe you got a bit tired towards the end and didn't do so well with questions 3 and 4.

The point is: Do you now understand percentages or do we need to give you some more questions to test your understanding? I would say that we do.

*Last edited by SteveB (2014-08-06 22:21:57)*

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

How about this for instance XXXOOOOOOO

There are 3 Xs and 7 Os there.

What percentage are Xs and what percentage are Os ?

Offline

**mandy jane****Member**- Registered: 2010-09-23
- Posts: 1,003

Hi Steve could I have some more percentage questions please to do?

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

Okay Mandy I will make up some new questions. The first one can be the one in post 1446. I may need half an hour at least to make up some questions.

Offline

**mandy jane****Member**- Registered: 2010-09-23
- Posts: 1,003

Ok Steve I will be back later today as I have to work this afternoon ok?

Offline

**SteveB****Member**- Registered: 2013-03-07
- Posts: 557

Question (1) Consider the following 10 symbols : XXXOOOOOOO

There are 3 Xs and 7 Os

What percentage are Xs ?

What percentage are Os ?

Draw a diagram with 100 items if it helps.

Question (2) Consider the following diagram:

OOOOOXXXXX

OOOOOXXXXX

OOOOOXXXXX

OOOOOXXXXX

OOOOOXXXXX

There are 50 symbols in total. Imagine that there were twice as many and in the same proportion.

What percentage are Os ?

What percentage are Xs ?

Question (3)

Draw a diagram that represents 25% Xs and 75% Os

The total number of symbols must be 8.

Question (4)

Draw a diagram in which 40% are Xs and 60% are Os.

The total number of symbols must be 20.

I will send you an email copy of that lot just in case it is easier to see in an email.

*Last edited by SteveB (2014-08-06 22:45:38)*

Offline