a) Customers can use a manufacturer’s coupon and a store coupon to obtain a disc

Question

a) Customers can use a manufacturer’s coupon and a store coupon to obtain a discount when buying soap powder in a certain store. In one week, 65 percent of the customers used the store coupon and 40 percent used the manufacturer’s coupon when purchasing the soap powder. 15 percent of the customers used neither coupon when purchasing the soap powder. What percent of the customers who used a coupon used both the manufacturer’s coupon and the store coupon?

b) If two dice are thrown, what is the probability that at least one of them shows a number greater than 3?

c) This is flu season. You have had your flu shot which is 90% effective at preventing the flu. Suppose that each flu season’s flu shot is 90% effective, but because of the changes in the strains of the flu, each year’s flu shot is independent of the other years. Assuming you get your flu shot every year, what are your chances of getting the flu at least once over the next 7 years?

Explanation / Answer

a) P(A) = 0.65 . P(B) = 0.4 P(A u B)') = 0.15

P(A u B) = 1 - 0.15 = 0.85

P(A and B) = P(A) + P(B) - P(A u B) = 0.65 + 0.4 - 0.85 = 0.2

b) probability tha number is greater than 3 = 3/6 = 1/2

the probability that at least one of them shows a number greater than 3 = 1 - probability that both shows a number less than or equal to 3

= 1 - 1/2 * 1/2 = 3/4

c) chances of getting the flu at least once over the next 7 years = 1 - chances of never getting the over the next 7 years

= 1 - 0.9^7

= 0.5217031

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.