Statistics And Probability Question 243
Question: Two friends A and B have equal number of daughters. There are three cinema tickets which are to be distributed among the daughters of A and B. The probability that all the tickets go to daughters of A is 1/20. The number of daughters each of them have is
Options:
A) 4
B) 5
C) 6
D) 3
Show Answer
Answer:
Correct Answer: D
Solution:
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Let each of the friend have $ x $ daughters. Then the probability that all the tickets go to the daughters of $ A $ is $ \frac{{}^{x}C_3}{{}^{2x}C_3}. $ Therefore $ \frac{{}^{x}C_3}{{}^{2x}C_3}=\frac{1}{20}\Rightarrow x=3. $
BETA
