math 2c

Test Preparation SAT Subject Test Preparation
1

<p>Hey. these are two sparknotes test questions that had an explanation that contradicted the actual multiple choice answer. Can somebody do these problems with the work shown so I can know which is the correct answer? thanks</p>

<ol>
<li><p>In a bag containing 6 oranges and 5 apples, what is the probability of withdrawing, without replacement, 1 orange and then 2 apples?</p></li>
<li><p>The probability of event A occurring is 1/3. The probability of event B occurring is 1/2, and the probability of both event A and event B occurring simultaneously is 1/5. What is the probability of either event A or event B occurring?</p></li>
</ol>

2

<ol>
<li><p>Total = 6+5 = 11 items
Prob of getting an orange = 6/11
Prob of getting an apple after this = 5/10
Prob of getting an apple after this = 4/9
Total Probability = (6/11)<em>(5/10)</em>(4/9) = 12/99 = 0.1212</p></li>
<li><p>P(A n B) = P(A) + P(B) - P(A U B)
P(A n B) = 1/3 + 1/2 - 1/5 = 19/30 = 0.633</p></li>
</ol>

<p>No guarantees that these are correct answers.</p>