Statistics And Probability Question 291

Question: From eighty cards numbered 1 to 80, two cards are selected randomly. The probability that both the cards have the numbers divisible by 4 is given by

[Pb. CET 2000]

Options:

A) $ \frac{21}{316} $

B) $ \frac{19}{316} $

C) $ \frac{1}{4} $

D) None of these

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Answer:

Correct Answer: B

Solution:

  •                 Total number of ways  $ ={{\,}^{80}}C_2 $                     and favorable ways  $ {{=}^{20}}C_2 $                     \ Required probability  $ P=\frac{^{20}{C_{_2}}}{^{80}C_2}=\frac{19}{316} $ .