<p>Btw guys, I’m mainly having problem with the “probability” and “graph” questions…what do you recommend for improving these two math portions?? :)</p>
<ol>
<li> Let’s say that the time it took her to get to work in the morning is t hours. Then the time it took her to get home in the afternoon must be 1-t hours. We know that for any trip, distance equals rate times time or d=rt. That means that the distance she drove to work is given by d=45t, but we also know that the distance she drove to get home must be the same distance, because she took the same route (and, presumably, no one picked up her house and moved it while she was at work) so for the trip home we can say and since the distances are equal, we can say: d=30x(1-t)</li>
</ol>
<p>45t=30x(1-t)
45t=30-30t
75t=30</p>
<p>t=30/75=2/5 @45mph</p>
<p>d=45 X (2/5)=18 miles</p>
<p>@ Reckie Wow! Thanks for the answer!! </p>
<p>What about question 1? Didn’t you try it?</p>
<p>For the second one you can also use the harmonic mean formula (aka Xiggi’s formula here):</p>
<p>avg rate for round trip = 2(rate 1)(rate 2)/(rate 1 + rate 2) = 2(45)(30)/(45+30) = 36.</p>
<p>So 2d = (36)(1) = 36, and d = 18.</p>
<p>For the first one, plug the two points into the given equation (they are on the graph after all):</p>
<p>You get 0 = p^2 - 4. So p=2 or p=-2
You also get 5 = t^2 - 4. So t^2 = 9. Thus, t=3 or t=-3.</p>
<p>Now the slope of the line is (t-p)/5. You can reason out which values for t and p will give the greatest slope, or to be safe you can just try all 4 possibilities:</p>
<p>(3-2)/5=1/5, (3–2)/5=5/5=1, (-3-2)/5=-5/5=-1, (-3–2)/5=-1/5. </p>
<p>So the gretaest value is 1.</p>
<p>@DrSteve Thanks for the first one, I only understood it the third time!! And yeah, for second one, Xiggi’s formula also works, but I prefer the Reckie’s technique for good perception…Xiggi’s method also faster than the other!!</p>
<p>scourge566 and others, when you are going back over your answers, ask yourself what the testmakers were trying to actually test you on. For instance, the one with the parabola and the line requires three key pieces of knowledge: 1) how to figure the slope of a line 2) that if two graphs intersect, the points of intersection will satisfy both equations and 3) that both a and -a will give you the same number when squared.</p>
<p>They always test the same concepts. This is what makes it a “standardized” test.</p>
<p>Thanks for the advice…and your time! 
I agree that the concepts are the same…I’m practicing the college board now,a full practice test per day “timed” but the thing is my mind always works slow on the probability and and graph questions…I finished the Barron’s MATH workbook first and also knew the the basic rules…but when it comes the BB math problems they are different from the Barron’s one and every practice set has at least a unique question!! </p>
<p>Out of those 8 practice tests I took whole 4 practice test in 4 days (1 test per day 3 hr 45 min) These are my math scores when I practiced:
1st BB practice test -650
2nd BB practice test -610
3rd BB practice test -630
4th BB practice test -620</p>
<p>Only 14 days are left for the DEC SAT!! I wanna boost my score this on 700s range…till the SAT say I’ll finish all 18 practice tests from PR and BB…Do u think I can boost my math scores by doing this??? What do u suggest?</p>
<p>scourge,</p>
<p>Your scores are very consistent but is the material you are missing consistent? The questions that you miss, do they tend to be the same type or are they different every time. My suggestion to you would be to take a day and instead of taking another practice test that day, go back and analyze the tests you have already taken. On a sheet of paper write down a description of every question you either answered incorrectly or omitted. With the data from four practice tests some patterns should be apparent. Perhaps you will notice that you struggle with the harder Algebra questions or some other type of question. You will have a better idea of which areas to concentrate on. If there is no discernible pattern, then the problem is elsewhere, maybe time management, maybe concentration. Just taking practice tests will not appreciably improve your scores, you must analyze your work and attack your weaknesses.</p>
<p>@pmian57</p>
<p>Today also, 630 in the 5th practice test 
(41 raw score/57)…Okay I’ll analyze the mistakes of these 5 practice tests immediately after this post. But each day after finishing the practice test I’m reviewing all my mistakes and practicing them though! Now my problem is only in the Math portion…Thanks for the suggestion!</p>
<p>in a geometric sequence of terms, there is a constant ratio between consecutive terms. of the sixth term of a certain geometric sequence with a constant ratio of 2 is 288, what is the first term of the sequence ? the answer is 9</p>
<p>If the constant ratio is 2, then the numbers are doubling, or halving depending on which direction you’re going. Since the sixth term is 288 and they want the first, keep diving by two.
Fifth term is 144
Fourth term is 72
Third term is 36
Second term is 18
First term is 9</p>
<p>Do you see how the constant ratio is two?</p>
<p>thnxs 4 ur help i didnot see the ratio is two . i need this questions<br>
in the xy-coordinate plane, the graph of x=y^2+1 intersects line l at (2,q) and (5,r) what is the greatest possible value of the slope of l ? i get the answer 1/3 but it is not correct the correct is 1 but i do not know why
2) an integer between 1 and 20 multiplied by itself can end in each of the following digits except (a)4 (b)5 (c) 6 (d)8 (e)9 the answer is d</p>
<p>bucket holds red balls and blue balls. the probability that a red ball is drawn at random is 5 /11. if a red ball is drawn first and not replaced, then what is the probability that the next ball drawn will be blue ?
the answer is 3/5</p>
<p>Ok I am reviving this because I don’t want a whole new thread for every question.
Can someone explain to me why the answer to this question is 23.3 (70/3)? I read the explanation and I just don’t get it.</p>
<p><a href=“http://img716.imageshack.us/img716/2229/screenshot20130104at628.png[/url]”>http://img716.imageshack.us/img716/2229/screenshot20130104at628.png</a></p>
![http://img716.imageshack.us/img716/2229/screenshot20130104at628.png[/url]](http://img716.imageshack.us/img716/2229/screenshot20130104at628.png%5B/url%5D){kind=link}
<p>@cutiedida There are a couple of ways to tackle this. But picking a value will work nicely.</p>
<p>We need the length both RS and PS to find the area of the rectangle.</p>
<p>You know that the area of the triangle is 7. So let’s just say that TS=7 and RS=2. That will give you a viable set of numbers that are 1) easy to work with and 2) fit the given information. </p>
<p>If PT= 2/5 of PS, then TS must be 3/5 of PS</p>
<p>Since we “decided” that TS=7 (14 would also work, if RS is 1), then that gives us: 7=3/5 of PS or 7=3/5 * x (since PS is the last piece we need). </p>
<p>Solve for x and you get 35/3 </p>
<p>Find area 2 * 25/3 = 70/3</p>
<p>Trying to decide if I’m Mathematically ■■■■■■■■ or not for not understanding your explanations ._.</p>
<p>There’s a typo…oops! The last line should be </p>
<p>2 * 35/3 = 70/3</p>
<p>Not 25/3</p>
<p>Hi everyone, I encountered this problem on SAT practice and I was confused.</p>
<p>Solve the system using any algebraic method.</p>
<p>x + 2y - z = 3
-x + y + 3z = -5
3x + y + 2z = 4</p>
<p>I came up with (8.16, -1.76, 1.64) but I tested out these points, and it worked for the first two equations but not for the third! Will someone please help?</p>
<p>@hichristen</p>
<p>You must’ve done something wrong in the work, then, because I got (2, 0, -1).</p>
<p>The easiest way to tackle the three equation problems is to eliminate. By this, I mean eliminating one variable in order to create two equations that you can work from.</p>
<p>I decided to eliminate the variable x.</p>
<p>So, combine the first two equations (by this, I mean adding them) and you should get this:
x + 2y - z = 3</p>
<h2>-x + y + 3z = -5</h2>
<p>0 + 3y + 2z = -2 => 3y + 2z = -2</p>
<p>(The ------------------ thing is the equation line like when you multiply vertically)</p>
<p>Next, I decided to combine the second and third equations because of the negative x. I don’t have to make things complicated with mixing up the negative and positive signs.</p>
<p>-x + y + 3z = -5
3x + y + 2z = 4</p>
<p>Multiply the top equation by 3 in order to set up the elimination of the variable x.</p>
<p>3(-x + y + 3z) = 3(-5)
3x + y + 2z = 4</p>
<p>-3x + 3y + 9z = -15</p>
<h2>3x + y + 2z = 4</h2>
<p>0 + 4y + 11z = -11 => 4y + 11z = -11</p>
<p>Now, you simplified this complicated three-equation problem into two equations that you can work off from.
Note: You can choose whatever variable to eliminate…I decided to eliminate y. So…</p>
<p>3y + 2z = -2
4y + 11z = -11</p>
<p>4(3y + 2z) = 4(-2)
(-3)(4y + 11z) = (-3)(-11)
(Multiply both equations to create the 12 and -12 required to eliminate y)</p>
<p>12y + 8z = -8</p>
<h2>-12y - 33z = 33</h2>
<p>0 - 25z = 25
-25z = 25
z = -1</p>
<p>Now, plug z into one of the 2 (y + z) equations and find y. Note: choose the much simpler one to work from…in this case, 3y + 2z = -2
3y + 2(-1) = -2 (Substitute z)
3y - 2 = -2
3y = 0 (Add 2 to both sides)
y = 0</p>
<p>Now, plug both y and z values into one of the three-variable equations and find x. Again, choose the easiest to work from…in this case, x + 2y - z = 3
x + 2(0) - (-1) = 3
x + 0 + 1 = 3
x + 1 = 3
x = 2</p>
<p>Therefore, the answer is (2, 0, -1)</p>
<p>Hope this helps! PM me if you are confused with my explanation.</p>