今年清大資應的機率論考題
困擾我很久>"<
希望有大大能幫忙解題
非常感激""
1.The probability that any paticular hard disk will fail during its Kth
year of use is given by the probability mass function for K.
P(K) = p * (1-p)^(K-1) ,K=1,2,3,...
(Express the answer in terms of p.)
(1)Four hard disks are tested simultaneously.Determine the probability that
none of the four disks fails during its first year of use.
(2)Four hard disks are tested simultaneously.Determine the probability that
exactly two hard disks have faild by the end of the third year.
(3)Four hard disks are tested simultaneously.Determine the probability that
exactly one hard disk fails during each of the first three years.
(4)Four hard disks are tested simultaneously.Given that one hard disk has
failed by the end of the first year,determine the probability that
exactly two hard disks have failed by the end of the third year.
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 122.126.110.34