The probability that a visitor at the mall buys a pack of candy is 30%.
The probability that a visitor at the mall buys a pack of candy is 30%. If three visitors come to the mall today, what is the probability that exactly two visitors will buy a pack of candy?
Answer/Solution
0.189
Steps/Work
0.3*0.3*0.7 is equivalent to saying the the first person picks candy and second person picks candy and third person doesn't pick candy.
however this is a different case compared to
0.3*0.7*0.3 is equivalent to saying the the first person picks candy and second person doesn't pick candy and third person picks candy.
which in turn is a different case compared to
0.7*0.3*0.3 (I'll skip the verbose comments)
Hence the answer is 3*(0.3*0.3*0.7)=0.189
ANSWER C
however this is a different case compared to
0.3*0.7*0.3 is equivalent to saying the the first person picks candy and second person doesn't pick candy and third person picks candy.
which in turn is a different case compared to
0.7*0.3*0.3 (I'll skip the verbose comments)
Hence the answer is 3*(0.3*0.3*0.7)=0.189
ANSWER C