Question

A soft drink company holds a contest in which a prize may be revealed on the inside of the bottle cap. The probability that each bottle cap reveals a prize is 0.2 and winning is independent from one bottle to the next. What is the probability that a customer must open three or more bottles before winning a prize

Answer 1

We conclude that the probability that a customer must open three or more bottles before winning a prize is P=0.64.

Explanation:

We know that the probability that each bottle cap reveals a prize is 0.2 and winning is independent from one bottle to the next.

Therefore, we get p=0.2 and q=1-p=1-0.2=0.8.

So we will calculate the probability that the buyer will not win the prize in the first and second bottles. We get:

`P=0.8\cdot0.8=0.64`

We conclude that the probability that a customer must open three or more bottles before winning a prize is P=0.64.

Answer 2

The probability that the customer must open 3 or more bottles before finding a prize is 0.64

Explanation:

In order for a customer to have to open at least 3 bottles before winning a prize, then the first two bottles shouldnt have a price. The probability that a bottle doesnt have a price is 1-0.2 = 0.8. Since the bottles are independent from each other, then the probability that 2 bottles dont have a prize is 0.8² = 0.64. Therefore, the probability that the customer must open 3 or more bottles before finding a prize is 0.64