Difference between revisions of "1995 AHSME Problems/Problem 20"
(→See also) |
|||
Line 13: | Line 13: | ||
== See also == | == See also == | ||
− | {{ | + | {{AHSME box|year=1995|num-b=19|num-a=21}} |
[[Category:Introductory Combinatorics Problems]] | [[Category:Introductory Combinatorics Problems]] |
Revision as of 07:53, 17 April 2008
Problem
If and
are three (not necessarily different) numbers chosen randomly and with replacement from the set
, the probability that
is even is
Solution
The probability of being odd is
, so the probability of
being even is
.
The probability of being odd is
and being even is
.
is even if
and
are both odd, with probability
; or
and
are both even, with probability
. Thus the total probability is
.
See also
1995 AHSME (Problems • Answer Key • Resources) | ||
Preceded by Problem 19 |
Followed by Problem 21 | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 • 26 • 27 • 28 • 29 • 30 | ||
All AHSME Problems and Solutions |