In a shop there are 40 customers, 12 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. 0.0223

B. 0.1426

C. 0.1142

D. 0.0335

Question

In a shop there are 40 customers, 12 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. 0.0223  
 
 B. 0.1426  
 
 C. 0.1142  
 
 D. 0.0335

anonymous · Answer

is it   A. 0.0223  

reqd prob = C(12,3)/C(40,3)

anonymous · Answer

or 
12/40 *11/39 *10/38 = 0.0223