Question 251232
let w=number within the limit and s=number of speeders.
(w+s)^2 We need  the term w^17s^6 
Combination: nCr = 23C17 = 100947 the coefficient of w^17s^6 
w=.60 s=.40
100947*.6^17*.4^6
=.070 the probability that exactly 17 are within the speed limit. 
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Ed