Don't laugh at me!

Buchanan0204

Buchanan0204

Buchanan0204

Soldato
Joined
10 Jun 2010
Posts
5,158
Location
Scotland
I'm trying to work out a stupid maths equation.

I want to know how much money I will have if I have to give away 30% of it.

I want to know how much I need to to make £500 for e.g.

I know to work out the percentage of what I have. I divide by the number and multiply by the % then subtract it from the total number. I thought multiplying it would be the reverse and give me what I'm after. I keep getting silly numbers in my calculator.

So I know I need around £725 to keep £500.

Can anyone tell me the actual sum that I need to do to work out future sums and of any amount.

P.S. I plan on saving 30% of my earnings over the next coming while to keep by until next year for a holiday. It's not homework haha.
 
Well if it is 30% then that means the number is 70% everytime.

So to find out how much money you have to make to keep £500 you would divide £500 by 7 then times it by 10.

I think.

So I think the sum is



Answer = (a / 7) x 10

a = Number you start with.


EDIT: To be honest I have probably read your post wrong and everything above is useless. But who knows.
 
Last edited:
nikeair94 said:
Well if it is 30% then that means the number is 70% everytime.

So to find out how much money you have to make to keep £500 you would divide £500 by 7 then times it by 10.

I think.

So I think the sum is



Answer = (a / 7) x 10

a = Number you start with.


EDIT: To be honest I have probably read your post wrong and everything above is useless. But who knows.
Click to expand...


ANOTHER EDIT: May as well do another example cause I am bored.

So lets say your goal was to save £200

£200/7 = £28.5714286

then multiply that by 10

£28.5714286 x 10 = £285.714286

So your answer would be £285.71 rounded to the nearest penny.

God I am stupid and should have listened in Maths.
 
nikeair94 said:
Well if it is 30% then that means the number is 70% everytime.

So to find out how much money you have to make to keep £500 you would divide £500 by 7 then times it by 10.

I think.

So I think the sum is



Answer = (a / 7) x 10

a = Number you start with.


EDIT: To be honest I have probably read your post wrong and everything above is useless. But who knows.
Click to expand...

Your a star! That's the one!!! Works a treat.

I hate math.
 
confused.com

You want to save 30% a month? Or want to save 500GBP and want to know how much you need total to save 500 - i.e. 725ish is the total and 500 is the 30% ?

edit: seems sorted ;)
 
OP could really be worded better to make it clearer what you want.

To be clear:

1) How much money do I need so that if I give 30% away I still have £500?
2) Give an algebraic expression for a given percentage "a" such that if you take a% from a given amount "y" you will have £500 left.

1) £500 x (100/70) = £714.29

- Check 714.29 - (714.29 x(30/100)) = £500

2) General formulae:

£500 x (100/(100-a)) = y. Where "a" is your general percentage and "y" is the amount you need.
 
Last edited:
ha ha calculator + all the maths equation replys

type this in

how much you want to make / 0.7 = answer every time


Oh and for when you actually know how much you made and want to know how much you have left after loosing 30% just x 0.7.

/thread
 
Last edited:
5punk3monk3y said:
ha ha calculator + all the maths equation replys

type this in

how much you want to make / 0.7 = answer every time


Oh and for when you actually know how much you made and want to know how much you have left after loosing 30% just x 0.7.

/thread
Click to expand...

You say that, but a post like this does not teach the OP anything really. Better to structure it out so they can learn from it clearer. It might be easy to you but clearly the OP struggles with maths.
 
8igdave said:
You say that, but a post like this does not teach the OP anything really. Better to structure it out so they can learn from it clearer. It might be easy to you but clearly the OP struggles with maths.
Click to expand...

Completely understand but I find a structured lesson would not be beneficial as this is basically 11 year old maths, so if he did not grasp it then why bother trying to "learn" him now.

In the OP he says he has a calculator and also wants the sum to work it out hence my post, which I'm sure if you read the OP again is actually what he asked for. :D
 
5punk3monk3y said:
Completely understand but I find a structured lesson would not be beneficial as this is basically 11 year old maths, so if he did not grasp it then why bother trying to "learn" him now.

In the OP he says he has a calculator and also wants the sum to work it out hence my post, which I'm sure if you read the OP again is actually what he asked for. :D
Click to expand...

Hahaha, true. If I'm honest I didn't actually understand the OP too well. I summized (sp?) my own conclusions and answered them.
 
Haha, I knew it wasn't right. I've become a grammar nazi ever since I decided to force my self into learning how to spell. I am a terrible speller when hand writing still but on the pc I'm pretty damn pro! :D

Same, I was going to start the gym up again tomorrow, can't see it happening now. Figured I'd give my self a few weeks to get all the binging at uni out the way before I started up again.
 
It seems to me that his question was only actually answered by me. He asked how much he needs if he wants to keep £500 after loosing 30%. You can only times by 0.7 if you know the amount you need in the first place. Otherwise you're picking out random numbers till you get £500 left over.
 
8igdave said:
It seems to me that his question was only actually answered by me. He asked how much he needs if he wants to keep £500 after loosing 30%. You can only times by 0.7 if you know the amount you need in the first place. Otherwise you're picking out random numbers till you get £500 left over.
Click to expand...

No, 500 / 0.7 = his answer, he already knew he wanted £500.
 
You must log in or register to reply here.
Back
Top Bottom