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?

(450/200)*100=225
450 end value
200 initial value
450-200 extra value ie increase = 250
250/200 X 100 = 1.25% increase

You are wrong.

Yes, write to them. Do not show them the photograph though - that would likely mean they would ban you.

Unless you meant that only mathematically incompetent people can work for the Civil Service, in which case I apologise!

I think the best thing to do is give the answer of 225% as that is what they obviously expect. Then feed back that you did this, but that in creating a narrative question they got mixed up between 100% as a whole number and a 100% increase, so the answer to the question they actually asked was 125%

Very good example with your saleslady. She may not be aware of what she is doing but politicians definitely are. They routinely underplay price increases and overplay the rare price reduction.

Am I missing something here @Sharingaroomtinightthen
Have you done the test and got your results ?
or are you asking for the answer here while you do the test at home?

Confused 🤔

Maths PhD and used to work in the civil service. OP is definitely correct. I’d let them know but maybe after things have progressed. Also, having recently moved to the private sector, I can confirm that there are mathematically incompetent people everywhere.

Year 1 end value = v
year 2 end = 3v
year 3 end = 3v x 0.75

(3v x 0.75)/v x100 = (2.25) x 100 = 225
the 0.75 above is the resultant value caused by the 0.25 (or 25%) reduction

I didn't read the full thread or all of OP's updates but it's 225

(450 / 200) x 100 = 225

According to Google's AI:

To calculate the percentage increase between 200 and 450, follow these steps:

1. Find the difference: Subtract the original value (200) from the new value (450).
2. 450−200=250
3. Divide by the original value: Divide the difference (250) by the original value (200).
4. 250/200=1.25
5. Multiply by 100: Multiply the result (1.25) by 100 to express it as a percentage.
6. 1.25*100=125%

Therefore, the percentage increase between 200 and 450 is 125%.

OP is right it is 125% a lot of people reading the question wrong. It's percentage from end of first yr to end of third yr.

I used to teach Functional Maths to adults (people aged 19-60). Most were perfectly competent in most areas of life, held down good jobs and brought up families. Very few understood percentage increase before I taught it to them (I like to think I remedied that) and a great many had difficulty with percentages in general.
As an aside, I estimated that about half the people who walked through my door were undiagnosed dyslexics - I sent loads for assessment.
The numeracy test for staff at that institution also had a blatant mistake on it, so when I did it I got the answer “wrong”.

Do you know what, I actually think the civil service might think it's 150%.

Second year it trebles - 200% increase
Next year it falls by a quarter - 200% minus a quarter is 150% if you're bad at maths.

So even giving the answer of 225% might not be "correct".

You’ve omitted the fact that the question asks for the % increase, not the % change in value.

Ah, pity you didn't. You have known why so many people are correctly saying the % increase is, in fact, 125%.

225% is the % of how much you now have, compared to the start.

125% is the % difference between the two quantities.

450 is 225% of 200, but if you’re wanting to work out the percentage increase from 200 to 450 it’s 450-200/200 x 100 = a 125% increase.

Young high school kids learn this in maths

@NeverWearingHeelsAgain with a maths PHD please tell me why my logic does not work as this is driving me insane.

After rereading and rereading I got the answer as 450%.

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

End of year 2 200

End of year 3 450

Difference 250 between end of year 1 to end of year 2 so 450% increase.

Please help me understand why this is wrong. C in GCSE maths 35 years ago!

It's not a badly worded question. That would be if it wasn't clear what it was asking or was ambiguous, which it's not.

Simply that none of the answers to choose from are correct.

No, it isn’t.

That's the % change in value but not the % increase, which is what the question asks. To calculate the increase you have to subtract the starting value from the end value, then calculate the change as a % of the starting value.

This has been hilarious to read.
It clearly says percentage increase in the question.
Formula is: Change in value divided by original amount * 100

They need to correct the wording in the question.

How are you going from 250 absolute number increase to 450% increase? I don't understand your logic there so I'm not sure how to show you why you're wrong!

I fear that if you use sentences like "I just seen" you won't pass the verbal test.

In what way am I wrong?

I’m unclear whether you’re really asking about the maths, or just playing with words to make a point that in your opinion only mathematically incompetent people would be a good fit for the Civil Service…