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?

Yup. I absolutely would have hit 225% in a multiple choice scenario - it being one of the steps along the way, and the power of confirmation bias.

Most if these tests have a bank of questions across various difficulty levels and you get a certain number of each.

It won’t be the same combination of questions every time.

Yes, and I think there's also an element of "how dare you question the answer provided by an authority," as though they are enjoying seeing the OP (incorrectly) being put back in her place.

Yes indeed. Also interesting to see the effects of "expert" testimony - i.e. people reporting that they are maths grads. I'm seeing strong primacy effects in this thread, people believing the wrong "expert" over multiple subsequent corrections.

All sorts of implications for how people end up with incorrect views about factually uncontroversial subjects like climate change, economics etc

@HornungTheHelpful have you actually read the thread where many posters have patiently and clearly explained why it is 125%??

There's been testing on this kind of thing.
Split people into two groups.
Groups A get given 4 questions they can solve, B get given 4 'impossible' questions.
Then give both the groups the same solvable 5th question.
Many more in A solve #5 correctly than B.
(No I can't give citation.)

Yes, that poster actually does understand, just got a bit confused because she was being incorrectly "corrected" by others. I didn't realize you were the poster she asked for clarification from though, makes sense that you would reply!

Popping this in before the thread closes! https://www.calculatorsoup.com/calculators/algebra/percentage-increase-calculator.php

I think it's a photo, so yes, anyone could do this. However, it's probably from a question bank, with a random selection being used to formulate each test, so you'd need to know multiple people who've done it to gain a significant advantage.

Someone'd better start a thread 6!

There are also practise tests available with similar answers. You also don’t normally do the test under exam conditions so you could definitely get someone to help you/do it for you if you wanted.

Ah ok that makes sense

It’s a photo but this thread has shown that people being told the correct answer doesn’t mean a thing.

BUT as countless pps have pointed out it doesn't ask for a percentage of what you had at the end of Y1. It asks for the percentage increase .

To all of you who think it's 225, just ask yourself this:

• if your salary was £200 and were offered a 25% pay rise, would you multiply by 25% bringing your salary to £50. Or would you add 25% bringing your salary to £250?

So, if your salary was £200 and you were offered a 125% increase then you would add £200*1.25=250 to your salary giving a total of £450.

Am I legally allowed to offer people oans with a "meager" 101% annual interest rate?

Seconding the call for a follow up thread
I'm curious to see how people respond after trying the calculator!

If a poster doesn’t read, comprehend or understand the very basic question in the photo in the very first post, I think it’s very unlikely that they have read or understood any of the calculations, correct and incorrect, set out in this thread, let alone explain why they believe the answer is not 125% :)

😂😂

Though, it does explain why so many people are so poor with money. If you don’t know the difference between between 1% and 101%, then the effects of compounding are going to blow your mind;)

Nice one! I’d like to see a comment from someone who has maintained that 125% is wrong.

I posted a screenshot shot from similar showing the answer around 20 pages ago. No one cares.

Just screenshotting from the calculator as it's so clear!

I have to confess when I started reading the OP (i.e. before I looked at the actual question) my expectation/assumption was that it would turn out she was mistaken.

But that may just be a function of my low opinion of other people's maths (and literacy) skills which has been pretty well borne out on this thread.

Seriously. What sort of Maths is that?

Of course, you might be joking.

Innumerate could well be the answer to your question :)

This thread, of all threads, has made me bemoan the loss of the laughing emoji as a response to a post

https://www.mumsnet.com/talk/am_i_being_unreasonable/5384612-maths-question-civil-service-is-wrong-we-now-have-100-more-threads-about-the-subject

Thread two. I am a glutton for punishment.