Statistics And Probability Question 527

Question: A and B toss a fair coin each simultaneously 50 times. The probability that both of them will not get tail at the same toss is

Options:

A) $ {{(3/4)}^{50}} $

B) $ {{(2/7)}^{50}} $

C) $ {{(1/8)}^{50}} $

D) $ {{(7/8)}^{50}} $

Show Answer

Answer:

Correct Answer: A

Solution:

  • [a] For each toss, there are four choices: (i) A gets head, B gets head (ii) A gets tail, B gets head (iii) A gets head, B gets tail (iv) A gets tail, B gets tail Thus, exhaustive number of ways is $ 4^{50} $ . Out of the four choices listed above, (iv) is not favorable to the required event in a toss. Therefore, favorable number of cases is $ 3^{50} $ . Hence, the required probability is $ {{(3/4)}^{50}} $ .