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

Isn’t it infinite subtraction, rather than divisibility?

Okay, subtraction - same comment devil and about 2nd bucket! Til tomorrow.

Same thing though - multiplication is just repeated addition, and division ...

I would just like to say that I was immensely tired when I posted on that other thread and I am not nearly as thick as I made myself sound!

Hahaha! I couldn’t resist the suggestion in the earlier thread 🤣

It’s 225%

No it isn't. They are asking for the increase, not the final value.

Oh FFS.

Which is not an option in the answers. It’s oddly worded but the maths adds up and can be back tested.

It’s not any of the options over 300. It’s not 150. Logic deduces 225.
Backtest OPs original 200 to 450 is 200 x 2.25 =450. Done. Tick box move on.

It’s like VAT. That’s 20%. You want to work it out it’s x 1.2 (120%).

It is 125% and the lack of right answer being given as an option doesn’t change that.

If you increased 200 by 100% what do you get?

I get why you are saying what you are saying also. It is a stupid question.

I am trying to think of how you could word the question better and I am stuck on that.

What percentage represents the change?

What is the percentage increase? It’s crystal clear.

@Nchangeo
"Percentage increase" is the normal terminology.

https://www.calculatorsoup.com/calculators/algebra/percentage-increase-calculator.php

I can't believe people are still not seeing that percentage and percentage increase mean different things.

Even if you're one of the many who's proudly 'bad at maths', it's very basic pre GCSE level maths. It's not like they're asking they're asking for the standard deviation at the 95% confidence interval.

the civil service presumably employs specialist test setters for this (but not specialist mathematicians)

You'd think, but no. My department runs a specialist training course for industry and as experts we've recently been asked to review the exam question set that's been the domain of the type of middle aged middle class white man who doesn't know much and doesn't do much yet doesn’t ever get questioned on this someone who has now retired and its dreadful. Genuinely ambiguous questions and a marking scheme that doesn't always include the right answers and allocates marks in a really inconsistent way.

So you've increased it by 20% when you multiply by 1.2

You've increased it by 20%
Your new amount is 120% of the original amount

If you increased 200 by 100% what do you get? 400, that’s what. 200% of 200. The only wording that could improve the question is a radio button with ‘125%’. Backtesting: none of the solutions is 125%. Its omission is an error, a mistake in the test. A stupid one. No need to be stuck - that’s it. The rest of the wording is fine.

Not even for the big civil service entrance exams? That surprises me a bit. For comparison, Oxford University outsources multiple choice question setting for its "Thinking Skills Assessment test" for entrance for PPE, while setting its own more subject specific entrance tests.

You might want to read the two whole threads on this before wading in confidently.

They've replied! "Let circulation at the end of year1= c. At the end of year2 it's 3c; at the end of year3 it's 2.25c. So the increase is 1.25c. This represents a percentage increase of 125% on c, the circulation at the end of year1. So none of the given options is correct."

Yes I saw that and clicked "thanks" to avoid diverting the thread from the pursuit of truth 😀

‘The pursuit of truth’ 😂. I hope this thread will one day be studied as a true example of speaking truth to power (in a roundabout way).

Ooooohhhh !!!! Some intrigue !

I wonder what on earth @cakeorwine could have posted on this thread to cause MNHQ to feel for the pearls ?

I wonder if it's the pelcgb word ?

Nothing too exciting. It's about someone trying to explain to a company that $0.002 per KB is not the same as 0.002 cents per KB.

And that if you multiply 0.002 cents * 35893 KB, you don't get $71.786

The person on the phone was struggling with the idea of 0.002 cents.