# 2006 STEP 2 Q6

The question on the question paper does not match the solution given. As shown in the link below:

http://postimg.org/image/p85p25oyn/

I think that the question is not the correct version. Firstly, it is way too easy, you just need to set a=1, b=c=2. Secondly, both the solution they give and people in TSR gives the answer x=7. Thirdly, it is completely unrelated with part ii, a huge massive jump from i to ii.

Am I correct to think that the question is not right. If so, any idea where I can find the correct question paper? I tried finding on the internet, but so far everything I found are the above version.

Thank you!

### Yes, part $\mathrm{(i)}$ is

Yes, part $\mathrm{(i)}$ is just a simple application of the preceding part and setting $a=1,\; b=2$ and $c=2$ is correct. I have no idea where $x=7$ comes from but the bit your circled in the solution I think is supposed to be read as a sentence i.e. $x=\frac{1}{2}\mathrm{this}$ where $\mathrm{this}=y=z$.

Also, part $\mathrm{(ii)}$ is related to the very first part of the question as you can use the very first part to calculate the solution. I'm sure there are other methods as well but I think the questions leads you to this particular method.

### The question is actually wrong

Thank you for your reply! Actually, my suspicion about the question is right. I have found the correct version of the question, as shown in the link below:
http://www.mathshelper.co.uk/STEP%20II%202006.pdf
So that version of the question is actually missing a sentence. Do you have any idea how I can tell the people at the STEP website that they have used the wrong version?
Otherwise, I think many more people like me will suffer in the future. It is not only this question which have a sentence missing. There is at least one other question on the paper that have a sentence missing. I know that because when I went to the STEP Easter school, I saw that correct version.

Cheers.

### 6ii

In 6ii - how do you know which vectors to use for [a b c] and [x y z] - is there any problem solving techniques to solve these kinds of questions? - i.e spotting key terms in the equations to help you choose the above vectors?

### Agree

Bit late to the party here. Just spent hours thinking that (i) lead into (ii). Had the entire question been there, it would've been more obvious that a different vector needed to be used :(

### ATS

2006 is before the Admissions Testing Service had anything to do with STEP (It looks like OCR was administrating them then).

I have let the powers that be know.

Underground Mathematics: Selected worked STEP questions

STEP Question database

University of Cambridge Mathematics Faculty: What do we look for?

University of Cambridge Mathematics Faculty: Information about STEP