several mediocre level problems from math 2

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1

<p>Hello Guys!</p>

<p>Lets concentrate on business!</p>

<p>1)sparknotes write me: If the range of a function is (–5, 5), this means that –5 is included in the range, but 5 is not. (The range is said to be “inclusive” of –5 but exclusive of 5.) The function whose graph shows this trait is the first one.</p>

<p>is it true?
i knew that [-5,5) is said to be “inclusive” of –5 but exclusive of 5 . Am i wrong?</p>

2

<p><a href=“http://imageshack.us/photo/my-images/823/60213917.gif/[/url]”>http://imageshack.us/photo/my-images/823/60213917.gif/&lt;/a&gt;&lt;/p&gt;

<p>The graph of y = f(x) is shown in the graph below. Which of the following statements must be true?</p>

<pre><code> I. The range and domain of f(x) are equal.
</code></pre>

<p>II. The graph of y = f(x) contains a horizontal asymptote at y = –1.
III. f(x) is an even function.</p>

<pre><code>(A) I only
(B) II only
(C) III only
(D) I and III only
(E) I, II, and III
</code></pre>

<p>answers tell that D is true.
So why?
question asks “MUST BE TRUE”.Its NOT always x=y .is it?</p>

3

<p>3)easy question from GMAT and Sat math level 2 barrons</p>

<p>GMAT:
The probability that tom will win the Booker prize is 0.5 and the probability that john will win the prize is 0.4.There is only one Booker prize to win.
What is the probability that at least one of them wins the prize?</p>

<p>Well,its simple: P(a)+ p(B) - p(AxB) or 1-(1-P(a))x(1-P(b))</p>

<p>But the i dont understand why barrons give me different solution about similar question:
page 188 question 23:</p>

<p>If the probability that the Giants will win the NFC championship is P and the probability that the Raiders will win the AFC( I THINK IT IS A SPELLING MISTAKE AND THERE SHOULD BE NFC) championship is q,what is the probability that only one of these teams will win its respective championship?</p>

<p>answer tells me : P+Q- 2PQ
AND NOT P+Q- PQ like in the previous example …So what the difference between the two questions?
are not they similar?</p>

4

<p>I agree with your reasoning on the first question.
I think the second question should be C.
For the GMAT one i think it should be 7/10.
The difference between the two is that in the GMAT one they are competing for the same prize, while in the Barrons one they are different prizes…</p>

5

<p>KingUncaged1
:slight_smile: i concur you,but sparknote doesnt :D</p>

<p>can u explain me why on the last question there is P+Q- 2PQ ??</p>

6

<p>If the probability that the Giants will win the NFC championship is P and the probability that the Raiders will win the AFC championship is q,what is the probability that only one of these teams will win its respective championship?</p>

<p>To figure out the probability of one winning the championship, we must find the probability of both not winning the championship, and the probability of none winning the championship and subtract it from 1(the probability of anything happening at all).</p>

<p>The probability of both winning: P*Q
The probability of neither winning is: (1-p)(1-q)
Therefore: 1-[pq+(1-p)(1-q)]
=1-[pq+(1-p-q+pq)]
=1-(2pq+1-p-q)
=p+q-2pq</p>

7

<p>i know this explanation.</p>

<p>does anyone have idea about first 1-2 questions ?</p>

<p>my teacher doesnt tell me that i was write,she was hesitate.</p>