Question

$70$ percent of the people in each of the $3$ rooms are seniors at university A. If one person is selected at random from each of the $3$ rooms, find the probability that each of the $3$ people selected is a senior at university A.

• A. $0.2401$
• B. $0.343$
• C. $0.49$
• D. $0.64$
• E. $0.7$

Answer 1

The correct option is B $0.343$

Given that: $70$ percent in each of three rooms are seniors in university $A$
Therefore probability of selecting a person from each room such that he is senior is $0.7$
Therefore probability that each of the $3$ people selected is a senior at university $A$ is $0.7\times 0.7\times 0.7=0.343$.