CK-12-Basic Probability and Statistics Concepts - A Full Course

http://www.ck12.org Chapter 2. Conditional Probability

2 0 MATH I I I (PRB) 3 (nCr) 7 ENTER

After pressing

ENTER

, you should see the following on your calculator’s screen:

Therefore,

20 C 7 =^77 ,^520

.

Thus, the total number of possible combinations is:

Rock Rap

20 C 12 × 20 C 7 =^125 ,^970 ×^77 ,^520 =^9.^765 ×^109 possible combinations

This means there are 9. 765 × 109 different ways can you select 12 rock songs and 7 rap songs for the mix CD.

Practice

1. Enter each of the following sets of keystrokes into your TI calculator to compute the corresponding combina-
   tions.


2. 
   

2 1 MATH I I I (PRB) 3 (nCr) 3 ENTER

3.

1 7 MATH I I I (PRB) 3 (nCr) 7 ENTER

4.

3 0 MATH I I I (PRB) 3 (nCr) 5 ENTER

5.

1 4 MATH I I I (PRB) 3 (nCr) 9 ENTER