Help with the math (how you approach the problems)

<p>Hi guys, I wanna know how you approach the questions ? how you deal with them ? Is there a problem solving process you are following ?</p>

<p>Many times i get stuck with hard questions and when my tutor explain the answer to me, it turns out to be easy and i may know the solution. When i see a hard question and can't solve it, i think it might be out of the syllabus but it sure doesn't. the question somehow got a kind of trick if i noticed it the rest is easy. So i need to know how to identify these tricks and how to approach these hard questions. The question is what is the difference between the mid 600s, 700s guy and the 800 guy ?</p>

<p>By the way i'm taking the math 2 and chemistry in November. So if you have any kind of tips for the chemistry to me it will be awesome.</p>

<p>All of the questions can be solved using techniques from basic algebra and geometry. Sometimes, the math problems might have a really long, brute-force solution, or an easy solution which could be tricky to find. Try the following problem:</p>

<p>If m and n are integers such that m-2n is divisible by 3, which of the following must also be divisible by 3?
A) m-n
B) n-m
C) n-2m
D) 2m-n
E) 2n+m</p>

<p>I think its D) . I plugged numbers for m and n m=5 and n=1 to make the result divisible by 3</p>

<p>But do you mean that all the questions in the test you can answer using the techniques in any sat math book for example like barron's. I study from barron's </p>

<p>I also want to know your mindset when you approach a math question. Is there a systematic approach you follow or problem solving steps ?</p>

<p>You are correct that it is D, but here is the reason why: we know that m-2n is divisible by 3 so 2m-4n also is. If 2m-4n is divisible by 3 then I can add any multiple of 3 and it will still be divisible by 3. I choose to add 3n. so 2m-4n+3n=2m-n is divisible by 3, which is D.</p>