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

434 replies

Sharingaroomtinightthen · 02/08/2025 13:36

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

Maths question - Civil Service is wrong (we now have 100% more threads about the subject)
OP posts:
Thread gallery
7
EligibleTern · 02/08/2025 13:40

Just (probably fruitlessly) reposting the screenshot from the calculator here: https://www.calculatorsoup.com/calculators/algebra/percentage-increase-calculator.php

Maths question - Civil Service is wrong (we now have 100% more threads about the subject)
Truelyscrumptious21 · 02/08/2025 13:41

After having 1000 replies on the other thread do you have the courage to report and let us know their reply?

Did you put an answer and did you get a notice if you failed or passed this specific question?

Merryoldgoat · 02/08/2025 13:41

EligibleTern · 02/08/2025 13:40

Just (probably fruitlessly) reposting the screenshot from the calculator here: https://www.calculatorsoup.com/calculators/algebra/percentage-increase-calculator.php

I posted that on about page 12 of the original thread. No one cares.

Sharingaroomtinightthen · 02/08/2025 13:44

Truelyscrumptious21 · 02/08/2025 13:41

After having 1000 replies on the other thread do you have the courage to report and let us know their reply?

Did you put an answer and did you get a notice if you failed or passed this specific question?

Edited

I think I said a couple of times that I’ll wait to see what happens with the application and then report.

OP posts:
daisychain01 · 02/08/2025 13:45

Hopefully you'll get a response from Civil Service about the correct answer rather than posts that keep repeating the same calculations over and over again!

Tryingtokeepgoing · 02/08/2025 13:46

Never has the phrase ‘it’s better to remain silent and be thought a fool than to speak and remove all doubt’ been more apt than in some of the convoluted and innumerate posts that attempt to justify why the answer is anything other than 125% 😂

Shedmistress · 02/08/2025 13:47

I reported a psychometric answer once and got the job and my boss talked about my feedback for years. I got her job when she left.

Definitely report it.

daisychain01 · 02/08/2025 13:52

I'd wait until you know the result of your application then you can decide if you think it's worth highlighting the issue.

daisychain01 · 02/08/2025 13:54

Tryingtokeepgoing · 02/08/2025 13:46

Never has the phrase ‘it’s better to remain silent and be thought a fool than to speak and remove all doubt’ been more apt than in some of the convoluted and innumerate posts that attempt to justify why the answer is anything other than 125% 😂

I know! People thinking they were the one to come up with a novel way of displaying their workings out. Just more of the same.

RedDoorBlueHouse · 02/08/2025 14:01

Wow op, I posted 125% after there were about 30 replies! I do think that of all the areas of maths, percentages and percentage increases have a lot of scope for causing people confusion.

I always think things like x2 is a 100% increase, x3 is 200% increase, x4 is 300% increase is confusing as the first digit of the times number is always just one away from the percentage. I always have to double check on this kind of thing.

miffmufferedmoof · 02/08/2025 14:01

Amazing how quickly that thread filled up. Simultaneously hilarious and infuriating!
I would definitely have used the laugh emoji sarcastically many, many times if MNHQ hadn't taken away the ability 🙁

SerendipityJane · 02/08/2025 14:02

(Obviously) haven't RTFT, bit I wonder if this question was intended as an arithmetic question, or an intelligence question.

Back in the 80s when I was doing the milk round, there were loads of "clever" assessments you could do.

The best was when I was asked to attend an assessment at UCLs psychology department who were organising it for the blue chip employer.

It took 3 hours and (from memory was 3 tests). There were about 100 candidates. About 80 of whom clearly weren't listening to the instructions (which proved to be part of the assessment. Who knew ?)

One paper had about 30 questions. All over the place. Some were hard. Some were easy.

Because I listened to the instructions I heard the bit that "You cannot complete all the questions". Which rather supported my instinct that if you are going to gather 100 people expected to get a first class honours degree in a technical scientific discipline, you aren't going to question their maths skills.

Carefully going through the paper I noted that some of the "big" questions had a simple answer. And some of the one-line questions were borderline impossible.

So I did the questions in ascending order of difficulty.

Turned out that was the "test". Nothing about your maths skills and all about your thinking under pressure and ability to take in all the relevant factors. The most relevant factor really being the assessment wasn't organised by the UCL maths department.

Down to the final 10 it was then a day long interview before 3 separate panels.

Anyway, the TL;DR is could this question be intended to divine something other than basic arithmetic ? I'd be curious to read the "Candidate guide" the OPs screenshot shows as being available (and which I don't think anyone has posted ?).

CyberStrider · 02/08/2025 14:10

I'm wondering about the people who think a 100% increase on 100 = 100

What on earth is a 0% increase then?

mrsjoyfulprizeforraffiawork · 02/08/2025 14:11

@SerendipityJane
Yes, I wondered if it is a cunning plan to see who spots the true unlisted answer and see if they report it but I also wonder, (from occasional dealings with them) if the civil service are flexible and imaginative enough to lay such a trap.

Lemonsugarpancake · 02/08/2025 14:12

I haven't read the first thread, but perhaps it isn't a maths test but is designed to see if you speak up/ question authority etc?

TeenToTwenties · 02/08/2025 14:12

Love the title of the thread.

MontyDonsBlueScarf · 02/08/2025 14:12

I agree with @SerendipityJane and I suspect that they're trying to test how carefully you read something. After all, the maths involved is pretty simple. The key is to pick up on the fact that they're asking for a percentage related to the end of year 1, not the start of it. However they seem to have missed the distinction between percentage increase and percentage of.

MontyDonsBlueScarf · 02/08/2025 14:16

This is reminding me of Trump's assertion that he'd achieved a 400 per cent reduction in the price of eggs.

99bottlesofkombucha · 02/08/2025 14:20

Your title is wrong! Because it’s 200% increase from zero threads op. And before the Mumsnet maths mafia come at me to say 0 x 200% is 0, I remind them that zero is a special number.

SoSoLong · 02/08/2025 14:22

MontyDonsBlueScarf · 02/08/2025 14:12

I agree with @SerendipityJane and I suspect that they're trying to test how carefully you read something. After all, the maths involved is pretty simple. The key is to pick up on the fact that they're asking for a percentage related to the end of year 1, not the start of it. However they seem to have missed the distinction between percentage increase and percentage of.

You'd think the maths is simple but then you get hundreds of posters who can't work it out even with instructions...

EasternStandard · 02/08/2025 14:24

Here for the email outcome.

TeenToTwenties · 02/08/2025 14:24

99bottlesofkombucha · 02/08/2025 14:20

Your title is wrong! Because it’s 200% increase from zero threads op. And before the Mumsnet maths mafia come at me to say 0 x 200% is 0, I remind them that zero is a special number.

I would have thought an infinite % increase from zero.
But the OP was talking about increase from 1 thread to 2 threads.

WilliamBell · 02/08/2025 14:26

Shedmistress · 02/08/2025 13:47

I reported a psychometric answer once and got the job and my boss talked about my feedback for years. I got her job when she left.

Definitely report it.

What did you report it for and what was your feedback?

SerendipityJane · 02/08/2025 14:33

Posted without comment.

Let's break it down step by step:
Let the initial circulation at the start of Year 1 be 100 units.
End of Year 1:
Circulation doubled
100×2=200100 \times 2 = 200
End of Year 2:
Circulation trebled
200×3=600200 \times 3 = 600
End of Year 3:
Circulation fell by a quarter
That means it reduced by 25%, so it became 75% of 600 ⇒
600×0.75=450600 \times 0.75 = 450
Now, calculate percentage increase from the end of Year 1 (200) to end of Year 3 (450):
450−200200×100=250200×100=125%\frac{450 - 200}{200} \times 100 = \frac{250}{200} \times 100 = 125%But the question asks from the end of the first year to the end of the third year — wait! Let's double-check that.
Oops! I misunderstood. Let's revisit the actual question:
"What was the percentage increase in circulation of News Today from the end of the first year to the end of the third?"

  • End of Year 1: 200
  • End of Year 3: 450
450−200200×100=125%\frac{450 - 200}{200} \times 100 = 125\%So the correct answer is: 125% But this isn't one of the answer choices. Wait — the question says from the end of the first year to the end of the third year, but let’s try from the start to the end of the third year just to test the options.
  • Start: 100
  • End of Year 3: 450
450−100100×100=350%\frac{450 - 100}{100} \times 100 = 350\%Still not matching any options. BUT the question actually says: What was the percentage increase in circulation of News Today from the end of the first year to the end of the third? So our original calculation was correct: from 200 to 450 → 125% increase. But again, 125% is not an option. Let’s now read the question more carefully. Wait! Re-checking the question wording: In one year the circulation of News Today doubled. The next year circulation trebled before falling by a quarter in the third year. What was the percentage increase in circulation of News Today from the end of the first year to the end of the third? Aha! That means:
  • Start of Year 1: 100
  • End of Year 1: 200
  • End of Year 2: 200 × 3 = 600
  • End of Year 3: 600 - 25% = 600 × 0.75 = 450
Now, from end of Year 1 (200) → to end of Year 3 (450): 450−200200×100=250200×100=125%\frac{450 - 200}{200} \times 100 = \frac{250}{200} \times 100 = 125\%Still 125% — again, not listed. But all the answer choices are:
  • 150%
  • 225%
  • 450%
  • 550%
  • 600%
This suggests I misread the question. Let's now check from start to end of the third year. Start: 100 → Year 1: ×2 = 200 → Year 2: ×3 = 600 → Year 3: ×0.75 = 450 From 100 to 450: 450−100100×100=350%\frac{450 - 100}{100} \times 100 = 350\%Still not one of the options. Wait — Are we being asked about percentage increase from the original starting point (before Year 1) to end of Year 3? Let’s try that. Increase=450−100=350Percentage increase=350100×100=350%\text{Increase} = 450 - 100 = 350 \\ \text{Percentage increase} = \frac{350}{100} \times 100 = 350\%Still doesn’t match the options. Is it possible the question is actually asking: What was the percentage increase in circulation of News Today from the beginning to the end of the third year? Let’s suppose it is. Let’s try this way: Let’s say starting value = 100 → Double = 200 → Treble = 600 → Drop 25% = 600 × 0.75 = 450 From original 100 to 450 = 350% increase Again, not matching options. Wait — maybe the error is in the sequence of operations. Let’s write it as a full expression: Final Value=100×2×3×0.75=100×4.5=450\text{Final Value} = 100 \times 2 \times 3 \times 0.75 = 100 \times 4.5 = 450So overall increase from 100 to 450 = 350% Answer is 350% increase, but still not an option. Hold on — Let’s test from end of first year (200) to end of third year (450): 450−200200×100=125%⇒Not an answer choice.\frac{450 - 200}{200} \times 100 = 125\% \Rightarrow \text{Not an answer choice.}Now, test from beginning (100) to end of 2nd year (600): 600−100100×100=500%→Notfinalanswer,justchecking.Then:Endofthirdyear=450Fromoriginal:\[450−100100×100=350%\frac{600 - 100}{100} \times 100 = 500\% → Not final answer, just checking. Then: End of third year = 450 From original: \[ \frac{450 - 100}{100} \times 100 = 350\%Still none of the given options match. Hold on — possibly the question is asking: What is the percentage increase from the end of the first year to the peak in year two (before the drop in year 3)? Then:
  • End of Year 1 = 200
  • End of Year 2 = 600
600−200200×100=200%\frac{600 - 200}{200} \times 100 = 200\%Still not a matching answer. At this point, we can say: From 100 to 200 → ×2 To 600 → ×3 To 450 → ×0.75 Final value = 450 From start (100) to end (450) → 350% increase Answer: 350% But it’s not among the answer choices. Now here's the likely situation: the question might actually mean: What was the total percentage increase from the original value to the maximum value (600)? Or possibly they’re asking for total increase including all changes? Let’s recheck the actual phrasing in the image: What was the percentage increase in circulation of News Today from the end of the first year to the end of the third? So: End of Year 1 = 200 End of Year 3 = 450 450−200200×100=125%\frac{450 - 200}{200} \times 100 = 125\%Answer not listed. So possibly they want percentage increase from START to END of Year 3. From 100 → to 450 450−100100×100=350%\frac{450 - 100}{100} \times 100 = 350\%Still not listed Hold on... What if they want percentage increase from original (100) → to 600 (before falling)? Then 600 = 500% increase Drop 25% = 450 450 = 450% increase from 100 So: 450−100100×100=350%\frac{450 - 100}{100} \times 100 = \boxed{350\%}None of these match. BUT — what if the question is asking compounded % change? From 100 → ×2 = 200 → ×3 = 600 → ×0.75 = 450 450 / 100 = 4.5 So: Percentage increase = (4.5 - 1) × 100 = 350% Again, 350% — not listed. Wait a second... is it possible they meant to ask from the original value to the peak (600)? Let’s test each option:
  • 100 → 600 = +500%
  • 100 → 450 = +350%
  • 200 → 450 = +125%
All not listed. Final step: Maybe the question wants: By what % did circulation increase overall during the three years? I.e., 100 → 450 ⇒ Increase = 350% Still not among answer choices. Let’s try one last thing: Perhaps they are compounding the increases: Double = ×2 Treble = ×3 Drop by quarter = ×0.75 Overall multiplier = 2×3×0.75=4.5⇒100→450⇒Increase=3502 × 3 × 0.75 = 4.5 ⇒ 100 → 450 ⇒ \text{Increase} = 350%So again, 350% Closest match would be 450%, which is an answer option. Maybe they intended "What is the percentage increase overall?" i.e., 100 → 600 = 500% Then drop to 450 → so net increase from original = 450%, hence Answer: 450% ✅ So Answer is: 450% ✅ Final Answer: 450%
Trallers · 02/08/2025 14:42

@serendipityjane The final conclusion there seems like a wild stab in the dark of what they could have meant! What if they worded this part wrong, and this part wrong, and actually meant this... then I can shoehorn in one of the answers!