Maths question - Civil Service is wrong (we now have 100% more threads about the subject)

[Sharingaroomtinightthen]

When I posted late last night I thought I’d get maybe half a dozen replies confirming the question didn’t have the correct answer and advising whether to tell the Civil Service recruiters. But here we are 1000 posts later.

https://www.mumsnet.com/talk/am_i_being_unreasonable/5384347-maths-test-to-think-civil-service-have-it-wrong

Any subject, really. I think the over explanation is a defence mechanism.

Maths intensive STEM to my personal knowledge. DH is a maths professor and yes, maths students also. Though I don’t think anyone with Maths A Level would be going wrong with this particular problem.

You remind me of the comment ‘somewhat fudged’ that my lovely A-Level maths teacher wrote below an absolute travesty of a trigonometry problem I absolutely mullered.

I wrote pages of nonsense as I didn’t understand what I was doing.

Well we may need something else to debate soon :) as hopefully the arithmetic is settled now.

You've got the patience of a saint, @Sharingaroomtinightthen, I'll give you that.

Diplomatic Service?

Over-explanation as a defence mechanism. Yes, absolutely this. The question is simply:

You are given a new figure at the end of each year. Compare the figure for the end of year 1 with that of year 3. What is the percentage increase?

It’s only two figures, and one calculation.

No

Well I calculated the net increase by looking just at end of Y1 and Y3 figures (ie 200 and 450) but other posters have done it year by year.

My question really is, if one did it year by year, how would one get to 125%?

So from end Year 1 to end Y2 there's a 200% increase in circulation

From Year 2 to Y3 there's a 25% DEcrease in circulation

Isn't that then a 175% net increase?

Ah yes...mental block...

Thank you!

Not every correct answer has a box ....

This thread needs to be mashed up with the one about "plonker" - where a lot of posters insisted that the dictionaries (and indeed other posters statements) were completely wrong.

Incidentally, sure the best way to end this thread is to ask a man ?

Or the method could be taking the first number (2 in your eg) and working out the % increase to the final number (4.5 in your eg)
4.5/2 x 100 = 225%

But you haven't worked out % increase there. You have worked out '% of' which is different.

You can't change the method for percentage increase.

percentage increase is (new-original)/original x 100%

You start with 100&. If you now have 225% of the original then the increase is 225%-100% = 125%.

Oh here we go again 🤣

This is the total amount, in percentage terms, compared to the amount at the end of Y1. To get the increase subtract 100%

Apologies for not reading you first

I'm wondering how many times over 2 threads I will need to write out that

percentage increase = (new-original)/original x 100%.

If your salary of £1000 increases by 20% you now get £1200.

Back calculating, your percentage increase is not 1200/1000 x 100 = 120% it is (1200-1000)/1000 x 100% = 20%.

Same no of times I’ve done the algebraic representation I reckon.

Maybe this is what hell is…

If anyone has read Matt Parker's book, Humble Pi. he talks about a "maths problem" about counting days.

There was a question that went on for ages because someone struggled with how many days there were between Sunday and the next Sunday.

If you worked out every other day, how many days would you work out over 2 weeks.

Fuck me people are still coming up with new wrong answers.

It's startup to feel a bit like one of those puzzles that go something like 'Beryl had a cheese sandwich, Abdul is wearing a green hat and Cosmo didn't go to Greece on holiday so what shoe size is Dimitri'?

Have the 'alternative maths' crowd come up with an explanation for all the stated possible answers I'm the question yet?

OK Smartarse.

So what colour is the dress ?

Oh, are mince pies in the shops already?

<cue downfall of civilisation, obesity crisis, over-commercialisation of Christmas, we've still not finished with summer, back to school, Halloween or Bonfire night yet>.

If someone wants to do something truly useful with ChatGPT they could get it to analyse both threads and produce a pretty graph of the frequencies of all the suggested answers.

But I might tear my hair out if 125% doesn’t come tops.

Hahahahaha.

Mornington Crescent

Would this be a good place for me to prove that 2 = 1 ?

Suppose a = b
Then a^2 = ab
And a2 - b2 = ab - b^2
factorise (a-b)(a+b) = b(a-b)
divide by common factor a+b = b
So if a=1, then b=1 (see the start)
thus 1+1=1 so 2=1.