Question

The probability that an event A happens in one trial of an experiment, is 0.4. Three independent trials of the experiments are performed. The probability that the event A happens at least once, is

• A. 0.936
• B. 0.784
• C. 0.904
• D. None of these

Answer 1

Answer: (B)

0.784

Answer 2

Given that, P(A) = 0.4, P($\overline{A}$) = 0.6
P(the event A happens at least once)
= 1 - P (none of the event happens)
= 1 - (0.6) (0.6) (0.6) = 1 - 0.216 = 0.784