<p>question 15 from test#5 section 3 in the blue book is confusing. THe answer choice in the back of the book says the answer is 24 but i keep getting 48 as the answer. I looked up khan academy and they say then answer is 48 as well.</p>
<p>Could you post it here? I don’t have the BB with me but I’ll answer it if I see the question.</p>
<p>i don’t know if i’m allowed to copy the exact question so i will post the same numbers but written differently.</p>
<p>you want to make a team for basketball. 3 members are allowed on the team. you have 4 veteran players and 4 inexperienced players. a team consists of 1 vet and 2 inexperienced players. how many possible teams can you make out of that?</p>
<p>4C1 x 4C2</p>
<p>and yes, you are allowed to post exact questions.</p>
<p>anyone</p>
<p>10 char</p>
<p>oh i didnt see your post bigb. can you elaborate on the steps you took and why you used combination.</p>
<p>You can choose 1 out of the 4 veterans and 2 out of the 4 n00bs. For each of those scenarios for the veterans there’s that many scenarios for the inexperienced, so you multiply.</p>
<p>yea i know you multiply by why use combination instead of permutation. like i said i got 48 and so did khan academy but the answer in the blue book says 24. can someone else answer this?</p>
<p>In general, a permutation is used when order matters, and a combination is used when order doesn’t. Let’s say I have to pick 2 numbers out of 4: 1,2,3,4</p>
<p>There are 6 ways to do it. 1,2; 1,3; 1,4; 2,3; 2,4; 3,4. </p>
<p>If you did a combination, 4C2 = 6 as well.</p>
<p>Now if I said order matters, then picking 1 then 2 would be one way, and picking 2 first and 1 second would be another way. The numbers are still the same (1,2) but I’m giving importance to in what order they’re chosen.</p>
<p>As a result, you do a permutation 4P2 and easily see that there are 12 permutations.</p>
<p>aight thanks.
is khan not reliable then?</p>
<p>I’ve never used them, but CC is pretty reliable. We don’t make mistakes :]</p>
<p>Note that if you get stuck on this on the SAT, you can make a chart and count. I usually do that to check anyways.</p>
<p>Doing 4x4x3 would imply that the order of the novices mattered (i.e. a team of Novice 1 and Novice 2 is different from a team of Novice 2 and Novice 1).</p>
<p>Let Experts be A, B, C, D
Let Novices be 1, 2, 3, 4</p>
<p>4 possibilities for experts</p>
<p>Possible novice teams: 12, 13, 14, 23, 24, 34 for a total of 6</p>
<p>4 x 6 = 24</p>