<p>I've been practicing like crazy and I keep getting slapped in the face and being told that I can't do it by the problems I keep missing...</p>
<p>Problem #1, I'll be honest, I had no clue how to solve it, and I guessed.
20. For the function f, f(x+y)=f()*f(y) for all values of x and y. If f(x)>0 for all values of x, what is the value of f(0)
(A)1/2
(B)root(2)/2
(C)1
(D) root(2)
(E)4</p>
<p>Fill-Ins:
I will be honest, I had no idea how to approach this one too... I guessed 0 and got it right
n!=1<em>2</em>3<em>4...</em>n
For all positive integers n, n! is defined as the product of all the positive integers between 1 and n, inclusive. What is the hundreds digit of (11!)<em>(12!)</em>(13!)<em>(14!)</em>(15!)?</p>
<p>(for all of you that can't solve them, you may find solace in the fact that these aren't real college board problems)</p>
<p>yes sorry guys, i typed it really quickly. It is supposed to be f(x).</p>
<p>I figured out the explanation for the second one though</p>
<p>because all factorials>10! have the number 10, logically they would have lots of 0s, so… since (11!)<em>(12!)</em>(13!)<em>(14!)</em>(15!) has 5 10’s, it must have atleast 5 0s beginning from the ones digit.</p>
<p>my genius friend explained the first problem.</p>
<p>it says f(0)</p>
<p>so logically we would let x and y = 0 because 0+0=0 f(x+y)=f(0)
soooooooooooo
because f(x+y)=f(x)f(y), then its like a=a^2
SOOOO
it must be either 1 or 0 because 1=1^2 and 0=0^2 BUT the problem says f(x)>0 so it must be one.</p>
<p>These are questions are from the curriculum of an SAT prep company that I go to.</p>
<p>Can you solve the problems?<<<</p>
<p>Not really. You should ask your instructor to help you solve this problem AND ask him to show you a couple of similar problems from past exams. With the verifiable answers, you should try to ascertain the relevance and ask the forum to help you with questions that are not the usual garbage produced by amateurs. </p>
<p>There is so much money and time wasted by those charlatans who are too lazy to provide their students with relevant instruction and material.</p>
<p>These won’t help prepare you for the MATH sat section. The best way to improve is to use the math problems directly out of the Blue Book sold by College Board themselves</p>
<p>My opinion on this is, while it’s usually best to use official CB materials, problems like these aren’t “useless.” Of course, if they’re poorly written or contain a bunch of errors, then I’d actively avoid them.</p>
<p>The wrong of synthetic questions is that they are typically poorly written, often have bad answers or are grossly irrelevant to what appears on an official test. They also do not benefit from the experimental testing used by ETS, and perhaps by that other outfit in Iowa. </p>
<p>The questions are often overly complex and test arcane elements. Or they can be rather dumb like the factorial question discussed here truly is. Dumb because anyone with the ability to click on a calculator could find the answer easily. An ability that is neither tested nor rewarded on the SAT Reasoning test. Thus, clicking 15! and realizing the result ends with three zeros is hardly SAT material. Or realizing that 2 x 5 = 10 and that all factorials above 4 end up in zero.</p>
<p>While I hardly can suggest to have seen all questions, I happen to think that such a question would never appear in that format.</p>
<p>Regardless, my position is that there are plenty of official questions available and that there are NO reasons to waste time on synthetic questions, or rely on tutors who think differently.</p>