Maths test - to think Civil Service have it wrong?

[Sharingaroomtinightthen]

I’ve just applied for a Civil Service test. Part of it is passing a numerical test.

This is the question.

The answer is 125%. I’m sure of it.

If you start with £100, and in the first year it doubles it’s £200. So at the of year one it’s £200.

In year two it trebles to £600.

It then falls by a quarter in the third year to £450.

So end of year 1 - £200.

End of year 3 - £450.

It’s increased by 125%.

125% isn’t an answer option.

WIBU to email and tell them they’ve got it wrong?

Well what an eye opener this thread has been to the level of comprehension and understanding of basic maths of the average MN poster, as well as the calibre of those that set the questions for the civil service and of those in the civil service recruitment / HR team that approved them. No wonder the Treasury struggles to put together a coherent budget for the Chancellor ;)

The question as posted in a picture by the OP is perfectly clear.
There is only one correct answer to the question, which is 125%
The correct answer is not one of the options presented by the test.

Circulation trebled which meant it went up by 300%.
It then fell by a quarter which meant you lost 25%.
300% - 25% = 275%

I suspect that OP is a logic and language person for whom logic and language matters.

And if course it DOES matter.

Clearly 100% of 100 is 100

But a 100% INCREASE on 100 is 200

If the original question said

A newspaper sells 100 papers a year

After two years, its publication doubles. What is the % increase

It would be 100%

This. Good God, the level of maths comprehension on this thread is abysmal.

Lol.

I'm not NeverWearingHeelsAgain but to answer your question

At the start, circulation was 100.

End of year one circulation = 200

End of year two circulation = 600

End of year three circulation = 450

Yes, you're correct that the increase between the end of year one and the end of year three is 250.

So, the question is, how much is that increase when expressed as a percentage of the end of year one circulation.

(increase in circulation) / (circulation at end of year one) = answer

250 / 200 = 1.25 = 125%

No, when circulation trebles, it increases by 200%.
you multiply by 3, but that makes an increase of 200%

No. Circulation trebled. So it INCREASED by 200%.

There is no starting figure. The only information given is that the circulation doubled in the first year, so you use the increase as your base. It’s clearly defined. ‘What was the percentage increase in circulation of News Today from the end of the first year, to the end of the third. I can’t see any ambiguity at all.

I don’t think you understand percentages.
If a number trebles it does not increase by 300%, it increases by 200%.

If I say your salary is going up by 100%, that means it doubles. If I ate 5 biscuits yesterday and eat 10 today, I have increased my biscuit intake by 100%. If I eat 15 today, I will have increased my intake by 200%. Three times as many biscuits, but the increase is 200%. To calculate an increase you have to subtract the starting number.

I’ve given up if I had to choose an answer from the drop-down I would choose 450%. I can see the answer 125% is logical but that isn’t a choice and 450% is available and for whatever reason my brain has calculated 450% as the best option.

I have messed the years up here too! But given the drop down options I would choose 450%.

@LillyPJ

You are essentially suggesting:

Year 0: 50 units
Year 1: 100 units (double Year 0)
Year 2: 150 units (triple Year 0)
Year 3: 112.5 units (a 25% drop from Year 2).

In which case the answer would be 112.5% growth from the end of year 1 until the end of year 3, or 125% if measured from year 0.

But that isnt what the words "the next year circulation trebled" means.

If Year 1 was 100, Year 2 was 300 and Year 3 qas was 225.

The % increase from 100 to 225 is 125%

This is why I don’t use % format at work!

Imagine an Excel spreadsheet that needs to be filled in by a non-finance manager. Column A has your salary in. Column B is for the manager to enter your % pay rise in % format. Column C contains the formula A x B.

Can you see how that could go wrong? Manager 1 might enter 104%, Manager 2 might enter 4%, Manager 3 might amend the formula in column C to A x (B+1).

I don’t think it’s a black and white answer to the initial question at all. I would have got 225% FWIW (which is what a manager would need to input to get the correct pay rise in my fictional spreadsheet)

Based on the actual wording the answer is 125% but suggest you feedback that the wording or the options has a mistake - and re frame the wording to show how you could get 225% - you don’t want to piss off a potential employer

OP I am absolutely loving your persistence on this thread.

I’m just going to put this here to help you out:

https://www.skillsyouneed.com/num/percent-change.html

Had to put pen to paper!

I worked it based on end of Y1 as 100 to make it easier!

End of Y2 300 (trebled)
End of Y3 225 fell a quarter (300÷4=75,.300-75=225)

125 difference end of Y1 and Y3

Percentage increase = (difference/original ) × 100

(125 /100) x 100
125%

I think!

But with you OP!

Any manager who doesnt understand the difference between, say a 5% pay rise and a 105% payrise isn't going to be a manger for long.

No - I meant when it says the circulation trebled. It doesn't specify if it means trebled from the previous year or from the original figure (i e. doubled then trebled = times 6, or trebled overall = times 3.) I know the final part is asking about the percentage increase from the end of Yr1.

Well your 25% figure is wrong for a start. 25% of 300 is 75 not 25 so the figure would be 225% not 275% as you stated. That’s if it was right but it’s not.

You’re not being asked to provide the overall increase, you’re being asked to provide the % increase from the end of year one. So when you arrive at the 300% overall increase at end of year 2, you then apply the 25% overall reduction from end of year 3 to arrive at 225%. You then have to subtract the 100% increase from year one. Answer 125%

It doubled then trebled.

If you strained or ignored the meaning of words to arrive at your interpretation, then the answer could be 112.5%.

You can’t reword it to get 225% - that would be a totally different question. The mistake is not in the wording, it’s in the fact that the correct answer doesn’t appear in the options.

@Sharingaroomtinightthen to answer your original question, yes I think you should definitely let them know. The process you have to go through to become a civil servant is not easy (I have family members who have been through it) so you will be helping others by pointing this out. Good luck with the rest of your job application and I hope you get the role you want.

Yep, this.

I know this is even more stupid but as so many of you have pointed out my stupidity is on full display now so I am going to go for it 😂

I first got to 450% by this calculation

1 + 2 + 3 =6 minus a quarter = 4.5 which I then converted into 450%!!!!

I knew this was random so I went back to try and work out more precisely using 100 as a base percentage.

I bet you can all guess I was a problem student at school in Maths it’s a miracle I got a C at GCSE!

Still out of all the options on the drop down menu 450% is the only one now I can make fit.

In my experience even those who profess not to understand numbers or percentages are perfectly capable of spotting even a minor error in their pay! I do not believe anyone would think they had a 125% pay rise if their pay had gone from £200 to £250, which is what some of the calculations on this thread have tried to show. They’d all say they had a 25% pay rise.

And so I would be surprised if anyone would therefore confuse a % pay rise (4% in your example) with a salary expressed as a % of the original salary (104%). The problem with your spreadsheet is that you have put the wrong formula in column C. To be consistent with your column heading you should have used manager 3’s formula. I think I’d be putting that manager in charge :) There should not be any areas open to interpretation if you use the correct language and the correct formula. Anyone who sends out a salary spreadsheet without checking the formulae or locking the non-input cells deserves whatever confusion follows!