Question
Question: Anand plays with Karprov 3 games of chess. The probability that Anand wins a game is 0.5, looses wit...
Anand plays with Karprov 3 games of chess. The probability that Anand wins a game is 0.5, looses with probability 0.3 and ties with probability 0.2. If he plays 3 games then the probability that he wins at least 2 games is :
A
0.375
B
0.500
C
0.125
D
- 250
Answer
0.500
Explanation
Solution
P( at least 2 games) = P(2 games) + P(3 games)
= 3C2 (0.5)2 × (0.3 + 0.2) + 3C3(0.5)3
= 3× (0.5)3 + (0.5)3
= 4 × (0.5)3
= 4 × 0.125
= 0.500