a coffee shop collected the following information regarding purchases from 120 of its customers. 59…
a coffee shop collected the following information regarding purchases from 120 of its customers. 59 purchased coffee. 40 purchased donuts. 19 purchased coffee and donuts. complete parts a) through c). a) of those surveyed, how many purchased only coffee? (type a whole number.)
Answer
Explanation:
Step1: Use set - theory principle
Let (A) be the set of customers who purchased coffee and (B) be the set of customers who purchased donuts. We know (n(A\cup B)=120), (n(A) = 59), (n(B)=40) and (n(A\cap B)=19). The number of customers who purchased only coffee is (n(A)-n(A\cap B)).
Step2: Calculate the number
We substitute the values into the formula: (59 - 19=40).
Answer:
40