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?
* 0.343
* 0.147
* 0.189
* 0.063
* 0.027
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
probability-candy
This topic has expert replies
Well the answer should be .189
There are be 3 cases here ( for exactly 2 people to buy the candy)
1. Buy-Buy-DoesNotBuy or .3*.3*.7
2.Buy-DoesNotBuy-Buy or .3*.7*.3
3.DoesNotBuy-Buy-Buy or .7*.3*.3
In all these 3 cases there will be exactly 2 vistors buying the candy) So the total probability will be sum of these three which is .189
There are be 3 cases here ( for exactly 2 people to buy the candy)
1. Buy-Buy-DoesNotBuy or .3*.3*.7
2.Buy-DoesNotBuy-Buy or .3*.7*.3
3.DoesNotBuy-Buy-Buy or .7*.3*.3
In all these 3 cases there will be exactly 2 vistors buying the candy) So the total probability will be sum of these three which is .189
