Personal Question!! (dealing with combinations and permutations)

Test Preparation
1

<p>So, I understand that permutation is when order matters and combination does not.
But, when it comes to SAT questions… I get lost in a world of confusion…>.<
Is there a specific way to differentiate when to use permutation and combination?</p>

<p>For instance this question…</p>

<p>As shown above, a certain design is to be painted using 2 different colors. If 5 different colors are available for the design, how many differently painted designs are possible?</p>

<p>This question utilizes permutation… which I though it used combination…
UGHH!! Please help clear this cloud of confusion!!!</p>

2

<p>permuation is used if order does matter. I am extrapolating that the diagram is one where the picture depends on the order of the colors. Combination would be if the colors were mixed, thus the order of the choosing doesn’t matter.</p>

3

<p>You can choose 5 paints as your first choice, and 4 for your second.</p>

<p>So 5*4 = 20</p>