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Derive a cookie success rate and compare two minimum-packet methods
Temasek Bakery produces a large number of “lucky” cookies during the festive season. of these cookies contains a winning slip. The cookies are sold by packets. Each packet consists of 8 randomly chosen cookies and the mean number of cookies with a winning slip per packet is 3.2.
(i) Find the probability that a randomly chosen packet contains at most 4 cookies with a winning slip. marks
(ii) Anand buys 12 packets of cookies. Find the probability that there are more than 10 packets that contain at most 4 cookies with a winning slip. marks
(iii) Beng decides to buy packets of cookies. Find the least value of such that the probability that there is at least one packet that contain exactly 4 cookies with a winning slip is more than 0.90. marks
[2017/TJC/MYE/II/5]
CJC · Review Problems · Question 10
The success event is at most four in (i)/(ii), but exactly four in (iii).