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?

Have you tried AI before? You could use Microsoft Copilot without downloading anything. You could try talking through the math with it.

Not sure about the OP but the last time I did a civil service test, I was told that my score was in the 93rd percentile. That's how my result was presented to me. In other words, if you scored in the 93rd percentile, it means you scored higher than 93% of the other people who took the same test or were in the same group.

Oh well, if you have even a shred of self esteem left, then MN hasn't done its job properly 😃. Sometimes its sole function seems to be as a platform for people to try to bring down others to make themselves feel good.

Why are you using £100? The question is about the percentage increase between the end of year one and three.

And 100 to 450 is a 350% increase, not 450%.

I did and all the answers mirror this thread. This question has been making the rounds for years!

The maths graduate explanation of their answer of 450% makes sense to me.

I understand why I got to 450% it’s not as technical as the maths graduate explanation but it worked for me.

It would be good to know the official correct answer from the drop-down.

This thread is a terrifying indictment of a) the general standard of numeracy and b) the general standard of unjustified smugness. Of course it's 125%.

It’s not asking for the percentage of what I had.

Ha! 💯

The answer is 125%.

Of course it’s 125%. It’s not even complicated. Somebody should definitely tell them

They don’t give the answers.

In their post, that poster said:

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

Which they wrongly described as a 450% increase.

Do you follow that, with yours/their interpretation, the increase is £350, so would be a 350% increase of £100.

The end total of newspapers is not the same as the increase.

@Sharingaroomtinightthen there isn’t a drop down 125% option though what I meant to say was from the drop down menu on offer what was the correct answer? Do you know?

Just seen your update I bet you could get penalised for sharing answers if you got the results anyway. I’ve looked online. They’ve known about this question for years. I wouldn’t say anything to them as they must know it’s been online for years.

Good-luck with your future career in the Civil Service. Hope you get the job. 95% is an excellent score.

I would have answered 450% given the drop down options.

It is truly terrifying that maths graduates get this wrong.

Some are not reading the question, which clearly gives the starting point as end Y1. Then they seem to think that there’s no difference between a comparison of the two figures and a % increase. They apparently think that if something goes up from 100 to 300 that’s a 300% increase.

Presumably they all know that if their salary doubles it's an increase of 100%, not 200%.

At least, you would hope so…

No, she has said several times she doesnt know.

I think most od us suspect 225% was the designated 'correct' answer.

This thread is really interesting. Not from a mathematical perspective - OP is straightforwardly correct - but as a reflection of how people behave on this forum. I've often seen people behaving very authoritatively and wondered how much expertise they actually have, to be that assertive. Turns out, not very much.

The amazing thing about this thread is that absolutely no one is having problem working out the 25% decrease.

if we can all understand that a 25% decrease takes it from 100 to 75 (or whatever numbers you’re using) how can’t we understand that a from 100 to 125 it a 25% increase?

This thread is batshit . OP, can you run the country please?

Yes, speaking as a maths graduate I'm curious about where this person claims to have graduated from 😅

OP is of course correct, it’s 125% increase. You should definitely alert them to this. Concerned by some of the incorrect answers coming from self-proclaimed maths grads (as a maths grad myself!)

how can’t we understand that a from 100 to 125 it a 25% increase?

Please explain this part. I don't understand.

This thread (and the results of the vote) confirms my long-held suspicion that a large proportion of Mumsnetters struggle with reading comprehension!

25 is 25% of 100 so 100 to 125 is a 25% increase.

Love this

Indeed. I’m re-reading Kruger & Dunning (1999), which seems to apply here.