March 2012 SAT I Math Thread

<p>i didn’t put 10 i didn’t put 17 and i didn’t put the last option. I put 15…? niceboat im confused 4^2+1=17</p>

<p>@Niceboat</p>

<p>D is not correct. 4^2 + 1^2=17. C would be the correct answer.</p>

<p>5 x4= 20
20/2= 10</p>

<p>The area of the triangle can’t exceed 9.</p>

<p>@SatMaster and amH Oops</p>

<p>Fixed. I was right the first time. Just typed something out differently O_O.</p>

<p>The sum of squares question is 15. 4^2 + 1^2 = 17, so that’s wrong.</p>

<p>@how: I used law of sines, but reflecting back, I’m not exactly sure how you could get 6+2root3 by creating special triangles.</p>

<p>x^2 + 4x + 2b = (x+b)^2</p>

<p>b = 2?</p>

<p>Phew… sigh of relief if those questions I posted were experimental. Would like someone to confirm they haven’t see those questions though.</p>

<p>Sitting at -2 I think for Math (triangle problem and because I can’t count the factors of 30 correctly). Feel like its going to be a harsh curve…</p>

<p>@Niceboat
But the height of the triangle is no longer 4 when you reduce the length? When the length is 5, the height becomes 3.33 I believe based on the slope of the triangle. Thus the area of the smaller triangle is 8.33 I believe?</p>

<p>C was correct. 15.</p>

<p>@Sat.</p>

<p>Absolutely not lol. Common mistake. Height is always perpendicular to the base. You extend the base so it is easier to see. Height is still 4. The height never changes when you extend the base. But the height is always different depending on which base you choose.</p>

<p>@russgenious i definitely didn’t have the questions you’re worried about!</p>

<p>can someone please elaborate on the bar graph questions on the families and children? Can someone explain how they got the answer, for some reason i keep thinking i got 4.5 for it</p>

<p>@how and @thesmiter
one of the angles given was 60, the other 45. you make 2 special right triangles if you draw a line down the center.</p>

<p>@ yankee: I got 2 as well.</p>

<p>@ the smiter: I drew a perpendicular line so that there were 2 triangles (one with angle x and one with angle y). X was 45 and Y was 60. The bigger circle before division would have 75 as the third angle (180 - x - y). </p>

<p>In the y triangle, it would have 90 (due to the perpendicular line), y (60) and the third angle would be 30. From there, it was just having fun with “triangle friends” lol.</p>

<p>Think the hyp. of the y triangle was 4 x sqr root of 3 so the base was 2 root 3 since it was opp the 30 degree angle of the divided triangle.</p>

<p>@ justlovelife: I’m a lot happier lol - those questions tripped me up. :/</p>

<p>@pingpongman: multiply the number of families by the number of children. Ex: 50 families have 0 children = 0, then add all the products together. After that, divide by the sum of all the families. I estimated 3.2 at first based on the graph’s semi-bell curve, then checked it with math and got the same thing.</p>

<p>Pingpongman</p>

<p>It was bar graphs showing how many people have 0,1,2,3,4, or 5 childrens…</p>

<p>Answer was 3.1xxxxxx rounded to 3.2</p>

<p>i divided the triangle into two special triangles and somehow got 4 as the length of the base for the 30 60 90, and 8 for 45 45 90… which added up to 12. Probably made a careless mistake somewhere in there!</p>

<p>what was the 4 root 3 problem?..</p>

<p>what was the nonsense with the almost finished bridge?</p>

<p>@pingpongman you could also just look at the graph, and see that most families had three children, with slightly more families having 4,5, or 6 children than 0,1, or 2… so about 3.2</p>