Probability Question 14

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}} $

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Answer:

Correct Answer: A

Solution:

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}} $ .