Maths test - to think Civil Service have it wrong?

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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?

I got 450%. 100 doubled is 200, trebled is 600, take away quarter, 150, gives 450. 450% of 100 is the same as 100% of 450, so 450%.

If you actually want the job, rather than appearing to be that person, click 225% and move TF on..

Why are you multiplying 4.5 by 100?

You are trying to calculate the increase between the end of Year 1 and the end of Year 3.

Then you are expressing the increase as a percentage of the end of year 1 figure.

You keep repeating your point which is a meaningless one btw and also attempted by others on this incredible thread. The changes - doubling, trebling and then a quartering are from year to year sequentially. They cannot all be of the base year - because that is seriously meaningless bullshite.
year 1 end - double of 100% = 200%
year 2 end -treble of 100%=300%
Year 3 end -3/4 of 100%=75%
No point asking the question about percentage change. See it?

Your problem isn’t maths, it’s comprehension.

"Base circulation 100 copies equals 100% so 50 copies equals 50%"

There’s your problem. You are asked to calculate ‘from the end of year 1’. That’s your 100%, and it’s 200. You also need to understand the difference between ‘percentage increase’ and ‘total percentage’.

This thread is depressing. I am not very mathematical, but of course the answer is 125%, I worked it out in my head. People's attention to detail is awful and their reading comprehension and reasoning even worse. It's the dumbing down of society.

But once again, what original figure ? The only information you have is that it doubled in the first year and trebled in the second. So the logical progression is that it trebled from the figure at the end of the first year, since year ends are specific to the question. EG. Base circulation at the beginning of year 1 is 100 copies. Circulation doubled at end of year one to 200 copies. Then it trebled by end of year 2 to 600 copies. If you calculate the equation correctly it doesn’t matter what the base figure at the beginning of year one is, the end result will be the same.

This.

Oh noes! That person. The one who is actually competent.

Except, using your numbers, the question is clearly asking the % increase between 200 and 450. Not what percentage of 100 450 is!

To be fair, it is a Civil Service job. Is competence a core competency that’s needed? 😂

300% x 75% = 225%
What happened the first year is irrelevant, as it's from the end of year 1

Except year 3 end would be 3/4 of 300%, not 100%. That would = 225% and to calculate the percentage change you would need to deduct from that the 100% from year one to arrive at the correct figure of 125%.

Yes realised that immediately afterwards. Hadn't read question properly. So 125%

Hi OP - I'm a CS analyst and a former university teacher, who had to write lots of multiple choice tests in that role.

The CS likes the 'bigger picture'. If you're going through the assessment to be a statistician or operational researcher, the interview will count for a lot and they will be looking for you to demonstrate Civil Service behaviours - you need to focus on that!

When I was writing MCQs for degree modules, the occasional typo/error would slip through because exam setters were typically setting them for small groups, under time pressure. It would take me a day to write a test and one or two colleagues would check it over. It's not as thorough a process as, say, Edexcel or AQA would have to use when setting tests for tens of thousands. I once had to run to the exam centre to have an erratum slip added on the morning of an exam.

This test might well have been procured from a reputable external provider, so don't imagine that it was simple carelessness or innumeracy by a standing CS analyst. It will be flagged now as an unreliable question and just set aside once they're aware of it. The online test is partly there as a screener to make sure that people have adequate numeracy and are also motivated enough to actually complete it. The sheer numbers of applications can be very high, so a test helps reduce the number of speculative applications.

I hope you get shortlisted and that you join us soon! Recruitment is very tight at the moment because there is no money - and there's plenty of work to do. I'm advising friends that if they get an offer, they shouldn't count on there being lots of open recruitment over the next couple of years if they're in two minds, but accept it while they can. The salaries are really low, and it's not easy to get promoted right now because of the recruitment squeeze and lack of money, but the pension and supportive culture can make it worth it. I only joined last September, but was very impressed with the quality of the analysts when I joined. There is also lots of extra training and development available.

Good luck!

Wtf have I just read? 😂

A temporary brain fart, hopefully ?

OP, faced with that question l would have asterisked the question, showed my workings out for the right answer of 125% and pointed out that the correct answer doesn’t appear as an option.

I love you for getting 450% 🥰 There is no answer for 125% which everyone is saying is the correct answer and I can see why so the best option is 450% on the drop down!

No, at the end of year 1 (the starting point) the percentage increase is 100%, not 200%.

Your calculations are going from the start of year 2 which is not what the question is asking you to do. It is specifically saying from the end of year 1 so you need to take into account the end of year 1 increase.

Wait until you see her next post!

(Maybe it'll help?)

So do I 😃. Lesson in reading question properly.

The start of year 2 and the end of year 1 is the same thing.

I’m sorry if I am repeating. I have skipped all the posts. It’s 450% (Maths graduate) 🤓

You start with £100 then x2 then x3 then x0.75

2x3x0.75 is 4.5 = 450%

the 0.75 is a 25% decrease of the £600.

alternatively you can think: start with £100 and end with £450

100x4.5 is 450 so we use 4.5 which is 450%

I am following the "logic" of some here to its end. You have to understand what the base of comparison is and be consistent with it. They claim that the question is ambiguous as to what the base is and that there are other equally valid ways of reading it. This question is not an ambiguous question at all.