1995 AHSME Problems/Problem 20
Problem
If and
are three (not necessarily different) numbers chosen randomly and with replacement from the set
, the probability that
is even is
A.
B.
C.
D.
E.
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 | |
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