John Wiley & Sons TI-83 User Manual download pdf (Page 34)

Permutations

Another common function needed to compute dependent probabilities that uses factorial is the

permutation formula. The number of permutations is normally written as nPr; on the calculator

with the symbol P written between n and r, where n is the total number of elements, and r is the

number being selected. Permutations are used when trying to find all possible arrangements of

elements taken from a larger selection.

Let’s say that you wanted to find the number of ways six people could be arranged in ten

different chairs. You could solve this by 10 nPr 6 .

Type in the number 10.

Press the MATH key.

Press the ► to highlight PRB.

Press the number 2 key.

Press the number 6 key.

Press the ENTER key to get the value 151200.

Combinations

Another similar function needed to compute dependent probabilities that uses factorial is the

combination formula. The number of combinations is normally written as nCr; on the calculator

with the symbol C written between n and r, where n is the total number of elements, and r is the

number being selected. Permutations are use when trying to find all possible groupings of

elements taken from a larger selection.

Example: Ice Cream

An ice cream parlor has six flavors of ice cream. Kristen wants to buy two flavors of ice cream.

If she randomly selects two flavors out of six, how many possible combinations are there?

In order to find the number of ways of choosing two flavors out of six, we would need to type

6 nCr 2. The symbol nCr is also found under MATH page under PRB.

Type in the number 6.

Press the MATH key.

Press the ► to highlight PRB.

Press the number 3 key.

Press the number 2 key.

Press the ENTER key to get the value 15.

1 2 ... 29 30 31 32 33 34 35 36 37 38 39 ... 88 89

No comments

John Wiley & Sons TI-83 User Manual Page 34