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

2.6. Combination Problems http://www.ck12.org

We have multiple groups from which we are required to select, so we have to calculate the possible combinations
for each group (rock songs and rap songs in this example) separately and then multiply together.

Using TI technology: fornCr, type thenvalue (the total number of items), and then press

MATH I I I

(PRB) H H

(to number 3)

ENTER

. Then type thervalue (the number of items your want to choose), and finally, press

ENTER

.

Rock:

For the rock songs, you would enter the following:

2 0 MATH I I I (PRB) 3 (nCr) 1 2 ENTER

After pressing

ENTER

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

Therefore,

20 C 12 =^125 ,^970

.

Rap:

For the rap songs, you would enter the following: