Operation Manual

2-2 Math, Angle, and Test Operations
8202MATH.DOC TI-82, Chapter 2, English Bob Fedorisko Revised: 02/09/01 12:20 PM Printed:
02/09/01 12:36 PM Page 2 of 16
Getting Started: Lottery Chances
Getting Started is a fast-paced introduction. Read the chapter for details.
Suppose you want to enter a lottery where 6 numbers will be drawn out of 49. To
win, you must pick all 6 numbers (in any order). What is the probability of winning
if you buy one ticket? What is the probability of winning if you buy five tickets?
1. Determine the number of combinations possible.
On the Home screen, press
49
to enter the total
number of items. Press
 |
to display the
MATH PRB
menu. Press
3
or
† † Í
to select
nCr
. Press
6
to enter the number of items
selected.
2. Press
Í
to evaluate the expression. This is
the total number of possible combinations of 6
numbers drawn from a set of 49 numbers. With
one ticket, you have one chance in 13,983,816 of
winning.
3. To calculate the probability of winning with one
ticket, press
1
¥ y
ã
ANS
ä
Í
. The answer is
expressed in scientific notation on the TI
.
82
because it is so small. The decimal equivalent is
0.00000007151123842.
4. To calculate the probability of winning with five
tickets, press
¯
5
Í
. Again, the answer is too
small to display in fixed notation. The decimal
equivalent is 0.0000003575561921.