<p>Hello~ I've got a few math questions, and it would be really wonderful if I could get an answer + explanations from one of the math geniuses out there. Thanks!</p>

<p>Blue book; test 1; section 6; question 5 (p.408)</p>

<p>On the disk (of 6 equal sections) shown above, a player spins the arrow twice. The fraction a/b is formed, where a is the number of the sector where the arrow stops after the first spin and b is the number of the sector where the arrow stops after the second spin. On every spin, each of the numbered sectors has an equal probability of being the sector on which the arrow stops. What is the probability that the fraction a/b is greater than 1?</p>

<p>a) 15/36

b) 16/36

c) 18/36

d) 20/36

e) 21/36</p>

<p>The answer is a. Why is that?</p>

<p>Blue book; test 1; section 9; question 14 (p. 426)</p>

<p>If (a + b)^1/2 = (a - b)^-1/2, which of the following must be true?</p>

<p>a) b = 0

b) a + b = 1

c) a - b = 1

d) a^2 + b^2 = 1

e) a^2 - b^2 = 1</p>

<p>The answer is e. ???</p>

<p>and... Blue book; test 1; section 9; question 16 (p. 427)</p>

<p>Set X has x members and set Y has y members. Set Z consists of all members that are in either set X or set Y with the exception of the k common members (k > 0). Which of the following represents the number of members in set Z?</p>

<p>a) x + y + k

b) x + y - k

c) x + y + 2k

d) x + y - 2k

e) 2x + 2y - 2k</p>

<p>d is the answer.</p>

<p>Thanks for helping out!</p>