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

😫😫😫

I never thought that any thread would surpass the 'gmail has given my gmail address to someone else but with a dot in it and I'm getting the emails" thread for sheer repetition of utterly WRONG but here we are...

I had to quit reading the OP's original thread because the number of people insisting that they had come up with the "correct" explanation for it being 225% was depressing me more than I thought possible!

It's 125% and they have worded either the question or the answer incorrectly.

Nooo.

Assume sales to be 100 at the start, so 200 at the end of yr1. If the percentage increase between end of year 1 and end of year 3 were 450% then the sales at the end of year 3 would be 900 and they aren't.

I'm not a mathematician but assumed the starting circulation was 100. It doubles (100% increase) to 200 by end of yr 1. That 200 then trebles (300% increase) to 600 end of yr 2. Then drops by 25%. 25% of 600 is 150 so the end of yr 3 amount is 450.

The end of yr 1 figure was 200 so the difference between them is 250. What is the percentage increase, not quantity increase between 200 and 450? It's 125%. If you increase 200 by 125% you get 450. So the answer is 125%.

I can't work out why you are adding 300% and 150%.

@Spiderbitebatbite Permit me an analogy.

Step 1: I gather a crate of bottles of milk and an empty bucket.

Step 2: I pour a pint of milk into the bucket. One bottle is now missing from the crate. The bucket has 1 pint in it.

Step 3: To treble the amount in the bucket, I pour in two more pints. The bucket has increased to 3 pints. But it has only two more pints than in step 1. The increase is 2 pints. The crate has three bottles missing. But only two bottles have gone since step 1. I have taken two bottles to increase the bucket. An increase of two bottles.

In Step 3, I have increased the milk in the bucket by 200%. The total in the bucket is 300% of what I ended Step 2 with.

Increase 200%, total 300%.

300% plus 150 % equals 450%

Why on earth would you add these two numbers? What is that telling you?

My answer clearly demonstrates how I get to 450% over and over using different numbers the answer is always 450%. Just like others have bravely said and been berated for. There is an answer for 450% on the test which is an option for those of us who know how to work it out correctly would choose.

450% is the right answer.

Surely you can see if sales have trebled after year 2 the answer must be above 300% as a starting point! Work from there. I mean I concluded this after quickly reading the question.

The answer is 450% all you sheep can keep harping on about it being 125 % it won’t change the fact you are wrong and the glaringly obvious exclusion of this even being an option to pick says it all.

Surely you can see that if the question is asking for the percentage increase, not the percentage total, the answer is going to be less than the total percentage?

It might be easier for people if your starting point is 50.

So at the end of year 1 it has doubled to 100, then the maths look easier. It’s exactly the same as everyone has said, but because you start with 50 but the end of the first year is a nice round number (ie 100) then it feels simpler?

It’s still 125% but it might help visualise it?

@NoCommentingFromNowOn

50

As question states start at 100 after doubling 50

100
300
150

300 - 100 = 200 which represents 300%

200 minus 25% is 150 which is a 150% increase from 100 start

300% plus 150% is a 450% increase

The answer is 450%

@Spiderbitebatbite

well I get to 125% with different numbers over and over.

You being wrong repeatedly doesn’t make you correct.

The fact you don’t understand what a percentage increase is will mean you do the incorrect calculation over and over and get the wrong result.

You aren’t brave. You’re stupid. And not because you got the wrong answer, because in spite of very clear explanations using basic maths (not your convoluted bollocks) you can’t see why you’re wrong.

50
As question states start at 100 after the doubling 50
100
300
150

Why are you going from 300 to 150? Which bit of the question does that represent?
And, again, why are you then adding 300% and 150%?

@Spiderbitebatbite

Christ on a bike.

Y0 = x
Y1 = 2x (doubled)
Y2 = 6x (trebled 2x)
Y3 = 4.5x (fallen by a quarter of 6x which is 1.5x)

This is irrefutable and an extremely way to write the basics of the problem

Calculate the percentage increase at end Y3 from end Y2

so percentage increase when the start is 2x and the end is 4.5x

the VALUE of the increase if 2.5x

You [one] needs to work out the percentage 2.5x is of the starting value - 2x

2.5x / 2x = 1.25

multiply by 100 for the percentage - 125%

If you get anything else you are not answering the question asked.

I have demonstrated why the answer is 450% over and over just like a few others have. The fact is there is a drop down box with the correct 450% answer and not 125%. I mean it is so obvious.

I can’t simplify it anymore.

I know the correct answer is 450%.

Wrong. The fact that you state it has trebled one year means you must understand the answer has to be at least above 300%. I mean this is basic stuff!

What is 200+125% on a calculator?

What is 200+450% on a calculator?

Honestly it’s mind boggling.

I’ve done the calculation algebraically for a third time in the hope it will help people who are still confused but I won’t hold my breath.

🤣🤣🤣

You’re trolling aren’t you? Which part is wrong?

Surely this will be picked up by the media, and the question posed to the Civil Service to clarify? In the public interest? Or a FOI request to ask how many people give the correct answer of 125% (which will mean they have to admit the answer options are all incorrect)?

This is the best, and most bat-shit thread in a long time.

#team125%

100 to 300 is an increase of 200%, not 300%.

Try it on a calculator. 100+200%.

I think spider is on the wind-up....

@Merryoldgoat you can berate and make fun all you want. You are wrong. So wrong.

@Spiderbitebatbite

If something trebles it increases BY 200%

Take 2 as a starting point

2 x 3 = 6

the increase is 4 (6 - 2)

4 is 200% of 2

6 is 300% OF 2 but a 200% INCREASE

The clue is in the word represents! The key is in the fact that trebling represents a 300% increase.

I mean it’s so clear. I demonstrated how I got to 450% using the 50 starting point you wanted me to.

I can’t make it any clearer if you don’t grasp the basics.

i agree - otherwise it’s supremely depressing

OK. So you start with 50, then double to 100 in year one, treble to 300 in y2 then reduce by a quarter in yr3 to finish at 225.

If the answer really was 450%, you'd have to go from 100 in yr1 to 550 at the end of y3.

The correct answer is 125% - the test was wrong!