Question

The probability of occurrence of an event $A$ in one trial is $0.4$. The probability that the event $A$ happens at least once in three independent trials is:

• A. $1-0.784$
• B. $0.784$
• C. $1-0.216$
• D. $0.216$

Answer 1

Answer: (B), (C)

The correct options are
B $0.784$
C $1-0.216$

Probability that event $A$ occur $=0.4$
Probability that event $A$ does not occur $=0.6$
Probability that event $A$ occurs at least once in $3$ trials $=1-$ probability that event $A$ does not occur
$=$ $1-(0.6{)}^3$
$=1-0.216$
$=0.784$

Hence, options B and C are correct.