  # SAT QofDay

<p>Can anyone explain why it's 5/12 ?</p>

<p>I got it right, but I don't get it.</p>

<p>If you roll it twice its denominator is 36, but there are 5 numbers less than the other ones on first roll, so second roll is 10. Isn't it 10/36?</p>

<p>Look at the chart it gives in the answer. Count the ones that apply</p>

<p>Educating guessing gave me the correct answer here.</p>

<p>Never mind, I got it.</p>

<p>How do I do these questions?</p>

<p>18) If 2x + y = 14 and 4x + y = 20, what is the value of 3x + y ?</p>

<p>24) What is one possible value for the slope of a line passing through point (-1,1) and passing between points (1,3) and (2,3), but not containing either of them?</p>

<p>for # 18, just add the equations together to get 6x+2y=34 an then divide by 2. Thus the answer is 3x+y=17</p>

<p>For #24, just think of a point between 1,3 and 2,3. So I chose (1.5,3). Then using your point (-1,1) and (1.5,3) just get the slope. 3-1/1.5+1. So the slope could be 2/2.5. Hope this helps.</p>

<p>Linger, how do we know when to add or subtract systems of equations on the SAT (given #18 as an example)?</p>

<p>Well subtracting wouldn't give you the result you are looking for, so you kinda have to play around with it and understand that the test makers are obviously going to make it so that it can be solved easily with just a little bit of thought.</p>

<p>When 247 divided by 6, the remainder is r and when 247 divided by 12, the remainder is s. What is the value of r-s?</p>

<p>Both remainders are 7, so 7-7 = 0</p>

<p>And this one: Dogs in a certain kennel are fed Brand A and B dog food only. Of these dogs, 6 of them eat brand A and 15 eat brand B. If 4 dogs that eat brand B also eat brand A, how many dogs are in the kennel? Answer: 17</p>

<p>(I'm getting difficult-time wasting problems in the CB Red Book btw).</p>

<p>^ Bump....</p>

<p>The first one, the remainder, when 247 is divided by 6, is 1 and the remainder, when 247 is divided by 12, is 7. So 1-7=-6. Not sure why you got 7 and 7.</p>

<p>And for the other one I don't know how to explain it but I got it right. Hopefully someone else can explain it for you.</p>

<p>6 + 15 = 21 - 4 = 17. It is kind of hard to justify though. </p>

<p>Imagine a venn diagram, with 6 in Brand A and 15 in Brand B, but only subtract 4 from Brand B because only they also ate Brand A. All Brand A dogs only ate Brand A, while some Brand B dogs ate Brand A.</p>

<p>
[quote]
The first one, the remainder, when 247 is divided by 6, is 1 and the remainder, when 247 is divided by 12, is 7. So 1-7=-6. Not sure why you got 7 and 7.

[/quote]
</p>

<p>Ah, I made a little dumb mistake in the end.</p>

<p>I don't know if I can continue trusting the red book, but here's another one: If x^2 > x^4and x > 0, what is one possible value of x?</p>

<p>x=1/2, could be a possible value</p>

<p>@Seachai8644</p>

<p>Anything -1<x<1 works. Anything less than one, when multiplied by itself or any other number less than 1 will be less than the original. Negatives also work in this case because something to the ^2 and ^4 will both be postivie.</p>

<p>@Jayxbx</p>

<p>Negatives don't work bro. x has to be bigger than 0.</p>