Statistics And Probability Question 484
Question: A contest consists of predicting the results win, draw or defeat of 7 football matches. A sent his entry by predicting at random. The probability that his entry will contain exactly 4 correct predictions is
Options:
A) $ \frac{8}{3^{7}} $
B) $ \frac{16}{3^{7}} $
C) $ \frac{280}{3^{7}} $
D) $ \frac{560}{3^{7}} $
Show Answer
Answer:
Correct Answer: C
Solution:
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$ P $ (correct prediction) $ =\frac{1}{3} $ ; $ P $ (wrong prediction) $ =\frac{2}{3} $ For exactly 4 right predictions Probability $ ={}^{7}C_4{{( \frac{1}{3} )}^{4}}.\,{{( \frac{2}{3} )}^{3}}=\frac{280}{3^{7}}. $
BETA
