In a shop there are 25 customers, 20 of whom will make a purchase. If three customers are selected,
One at a time, at random, what is the probability that all will make a purchase?
A)0.5876
B)0.4957
C)0.6160
D)0.5069

Question

Quizplus · Accepted Answer

The probability that all three selected customers will make a purchase is calculated by multiplying the probabilities of each event happening in sequence. For the first customer, the probability is 20/25 (since 20 out of 25 will make a purchase). For the second customer, after one has already made a purchase, it's 19/24 (since there are now 19 who will make a purchase out of the remaining 24 customers). For the third customer, it's 18/23. Multiplying these probabilities gives (20/25) * (19/24) * (18/23) = 0.4957.

In a Shop There Are 25 Customers, 20 of Whom