Thread: omg probability is so hard!! =[[

can u show me how to do this step by step?








Jerry has a CD case that contains 4 country music CDs, 1 rock-and-roll CD, 2 rap CDs, and 3 Tejano CDs. What is the probability of Jerry randomly selecting a Tejano CD and then, without replacing it, randomly selecting a rap CD from his case? A

B

C

D

Originally Posted by whatxxever_2009

can u show me how to do this step by step?








Jerry has a CD case that contains 4 country music CDs, 1 rock-and-roll CD, 2 rap CDs, and 3 Tejano CDs. What is the probability of Jerry randomly selecting a Tejano CD and then, without replacing it, randomly selecting a rap CD from his case? A

B

C

D

The probability of drawing a Tejano CD is as follows:

There are 3 Tejano CDs, but we have 4+1+2+3=10 CDs total. So the probability of him picking a Tejano CD first would be . If he then picks a Rap CD without replacement, then the total number of possible CDs drops down to 9. Thus, the probability of him drawing a Rap CD after he draws a Tejano CD is

Does this make a little more sense now? If you're still lost, please post back.

Note that I moved your thread from the Geometry forum to the Probability and Stats forum.

oh ok. but why do u have to multiply them together? whenever i have a problem like this will i always have to multiply them?