In any one particular flowerbed:A seedling has a 0.7 probability of developing into a mature plant.
Seven flowerbeds are each planted with 20 seedlings.
Find the probability that at least 12 seedlings mature in exactly five of the flowerbeds.
The probability that at least 12 mature is the sum of the above probabilities.
. . Call this sum
We have a choice of 5 of the 7 flowerbeds: .
. . Therefore: .