SAT Math Help Final

Test Preparation SAT Preparation
1

<p>Please help and explain if you can.</p>

<ol>
<li><p>What is the greatest possible number of points common to a triangle and a circle?</p></li>
<li><p>In the figure, ABCD is a trapezoid and AC is the diagonal cutting ABC and ACD into two triangles. the area of triangle ABC is 1/2 the area of triangle ACD. If BC||AD and the sum of BC and AD is 18, what is AD?</p></li>
<li><p>On a certain radio station, every 4th song played is a golden oldie, and during every 5th song played, a prize is given away. If a song is selected at random from 100 consecutive songs that the radio station will play one night, what is the probability that the song will be a golden oldie AND a prize that wll be given away during the song?
A. 5/100 B. 9/100 C. 16/100 D. 20/100 E. 25/100</p></li>
<li><p>The chart below shows the location and distribution of all the people at the wedding party. If one person is picked for a celebration song, what is the probablity of selecting one in the dining room?</p></li>
</ol>

<p>Location Number of tables Number of people
Yard 4 6
Porch 3 2
Dining room 2 4</p>

<p>(Isn't either 2/8 or 8/38?)</p>

<ol>
<li>If the average( arithmetic mean) of 5 numbers is greater than 25 and less than 30, which of the following could be the sum of the 5 numbers?
A 150 B 144 C 125 D 110 E 100</li>
</ol>

<p>(I ruled out A and E since 30>five numbers/5 > 25 so 150>five numbers>100)</p>

<ol>
<li>In the figure it shows a 12 hour clock where it is currently 3:40. At any moment in the day what is the probablity of the minute hand's pointing between 10 o'clock and 12 o'clock?</li>
</ol>

2

<p>11) should be 6. (if you just think about a triangle that larger than the circle - the circle will meet the triangle at two points per line of the triange - ergo 6.)</p>

<p>12) I could be very wrong… but here’s what I thought…</p>

<p>The question basically tells you that both triangles are exactly the same, except for the base. (height is the same)</p>

<p>therefore, you can AD x Height = area … and … BC x height = area/2<br>
AD x Height = 2BC x 2Height
AD = 2(BC x Height)/Height = 2BC
AD = 2BC
System of Equations:
AD + BC = 18
-(AD - 2BC = 0)
3BC = 18
BC = 6
So AD = 18 - BC = 12.
AD = 12
(100% not sure if right answer.)</p>

<p>13) A is the answer I believe.</p>

<p>Since they will only play an oldie every 4
and given away every 5,
They will do both, every song that is a a multiple of both. So 20, for example.</p>

<p>The only multiples of both 4 and 5 under or equal to 100 are 20, 40 ,60 ,80 and 100. </p>

<p>So there are 5 times where they will do both for every 100 songs played. Therefore 5/100</p>

<p>14) Im assuming that number of people means number of people per table.</p>

<p>So there are 8 people in the dining room. and 24 + 6 + 8 people in total.</p>

<p>So its 8/38 chance.</p>

<p>15) 25< fivenumbers / 5 < 30</p>

<p>125 < fivenumbers < 150 – you were so close, just had a mathematical brain fart.</p>

<p>only number that satisfies is 144, B.</p>

<p>16) I’m not sure whether the time is 3:40pm and we are supposed to check the probability of it being between 10 and 12 o clock for the rest of the day - which would be a time period of 8 hours and 20 minutes, or just a generic day.</p>

<p>if its the first case, it would be </p>

<p>(8x10 + 10) / (8x50 +10) + (8x10+10) = 90 / 500 = 9/50 or 0.18</p>

<p>or if its a generic day, just think ok… the minute hand will be between 10 and 12 for 10 minutes every hour and not for 50 minutes every hour. 24 hours in a day, so 24x10 / 24 x 50 +240 = 240 / 1440 = 1/6.</p>

<p>— I’m not 100% sure on some of these questions :(</p>