In a marketing survey involving 1,000 randomly chosen people, it is found that 630 use brand P, 420 use brand Q, and 210 use both brands. How many people in the survey use brand P and not brand Q?
Answer choices:
210 people
420 people
630 people
none of these
3 answers
(Weighing produce). A supermarket has three employees who package and weigh produce. Employee A records the correct weight 98% of the time. Employees B and C record the correct weight 97% and 95% of the time, respectively. Employees A, B, and C handle 40%, 40% and 20% of the packaging, respectively. A customer complains about the incorrect weight recorded on a package he has purchased. What is the probability that the package was weighed by employee C?
x + 210 = 630
x = 420
x = 420
A wrong .02 * .4 = .008
B wrong .03 * .4 = .012
C wrong .05 * .2 = .01
total wrong = .03
C wrong/total wrong = .01/.03 = .33
B wrong .03 * .4 = .012
C wrong .05 * .2 = .01
total wrong = .03
C wrong/total wrong = .01/.03 = .33