math help

Test Preparation
1

<p><a href="http://i40.tinypic.com/2qs00vl.jpg%5B/url%5D"&gt;http://i40.tinypic.com/2qs00vl.jpg&lt;/a&gt;&lt;br>
the answer (B)</p>

2

<p>Best thing to do is draw a picture. Let’s say points A, B, and C lie on line l, and C, D, E lie on line m. We want to pick lines that pass through exactly two of {A,…,E}.</p>

<p>First off, such a line can’t pass through C, otherwise it would pass through exactly one or three points. It turns out that all possible lines pass through one of {A,B} and one of {D,E}. Since there are 2 ways to pick one point from {A,B} and two ways for {D,E}, the total number of lines is 2*2 = 4, B.</p>

3

<p>thnx u i got it !!! but can u help with this one <a href=“http://i41.■■■■■■■.com/x5o86t.png[/url]”>http://i41.■■■■■■■.com/x5o86t.png&lt;/a&gt;&lt;/p&gt;

4

<p>Sure. For this problem, think about what doubling the angle or radius does to affect the area of the sector POQ. Notice that if we double angle POQ, the area of the sector doubles. If we double the radius (OQ), the area is multiplied by 4. Therefore the area of sector RST is 3<em>2</em>4 = 24.</p>

5

<p>thnx u miter 94 but can u answer these </p>

<p>A circle has an area of 25 pi and is divided into 8 congruent regions. What is the perimeter of one of these regions?
a) 10 - 25pi
b) 10 + 5/8pi
c) 10 + 5/4pi
d) 10 + 5pi
e) 10 + 25pi</p>

<p>(C)</p>

6

<p>I’m assuming the regions are pie-shaped.</p>

<p>First find the radius of the circle. Then what is the circumference? Once you have those the problem should be easy.</p>