Official Act Math Thread February 2013

<p>Here seems to be the general consensus for the questions:
Probability question = {3/4}
Period= 4 pie
Town question= 12
Total hours read question = 24n
Radius= 5</p>

<p>Any nay sayers???</p>

<p>Can someone explain the spinner? I got 1/2</p>

<p>Poppers you can add the adult ticket one, and the book salesman one.</p>

<p>Tips, what did you get for the radius one?</p>

<p>Explanation of Probability Question: There’s a spinner that has equal areas of green, blue, purple, and yellow sections. There’s a bag that has 3 green, 4 blue, and 5 purple marbles. 12 marbles total. What are the odds you will choose different colors? (Note: colors are probably wrong, but the important thing is that there is no yellow in the bag).</p>

<p>I solved it by finding the odds of landing on drawing each color twice.</p>

<p>Green: (1/4) x (1/4) = 1/16
Yellow (1/4) x 0 = 0
Blue (1/4) x (1/3) = 1/12
Purple (1/4) x (5/12) = 5/48</p>

<p>Add up all the probabilities:</p>

<p>(1/16) + 0 + (1/12) + (5/48) = 1/4</p>

<p>Odds of NOT drawing the same color twice:</p>

<p>1 - (1/4) = 3/4</p>

<p>Kongo, you are right for the 1155 pencils… no questions.</p>

<p>Thanks for showing your work on probability!</p>

<p>@poppers i got 5 for the radius.</p>

<p>for the pencil selling one i believe it was 1,155 or something</p>

<p>Thanks tips!</p>

<p>Here seems to be the general consensus for the questions:
Probability question = {3/4}
Period= 4 pie
Town question= 12
Total hours read question = 24n
Ticket one- 150 adult, { 200 children }
Pencils- 1155
Any nay sayers???</p>

<p>Can we make a decision on the ellipse one. One person said x^2/9 + y^2/16 = 1</p>

<p>the pencil was 1155,
can anyone confirm my answer of 2sqrt3 for the box inside of a sphere? i believe the side lengths were 4 so you did sqrt(4^2+4^2+4^2) then divide by two to get the radius of the sphere = 2sqrt3?</p>

<p>@poppers i also got x^2/9+ y^2/16 =1</p>

<p>dlee can you put up the question a little clearer. I dont remember what I got but I know i got the answer</p>

<p>The radius of the sphere had a triangle with the hypotenuse being the radius, one side was 3 and the other was 4, the hypotenuse was 5.</p>

<p>Could someone explain the n books problem? I feel so bad for not remembering it exactly.
It was something like 1/2 of the class read F and N, 1/4 read F and B, and 1/4 read N and B. F books took like 10 hours, B books took 12 hours, N took 14 hours. Those numbers and whatnot are probably interchangeable, I think I wrote that wrong.</p>

<p>i didnt even have that question… what number was it???</p>

<p>Thanks tips!</p>

<p>Here seems to be the general consensus for the questions:
Probability question = {3/4}
Period= 4 pie
Town question= 12
Total hours read question = 24n
Ticket one- 150 adult, { 200 children }
Pencils- 1155
Ellipse- x^2/9+ y^2/16 =1
Any nay sayers???</p>

<p>the book problem, u could have literally just made n=20. then FN would be 10 people. 5 would be FB and 5 would be NB. then you just add the hours, and it equals 480. so that means 24n.</p>

<p>the length of the sides of the cube inside the sphere were 4, so the vertical leg of the triangle was 2
@delayed
the hypotenuse was not 5 i know that much</p>

<p>Diddly, I think we had different forms. I didn’t have the one on the sphere with a triangle inside…</p>

<p>Oh was the distance from -6 to -11 5? I got -5, but distance is always positive so…</p>

<p>Thanks delayed, I remember now. Delayed is right because through Pythagorean theorem you can find the hypotenuse { A.K.A the radius } given two sides of the triangle.
That is my 2 cents
Hope that helps dlee!</p>