Question 1175389
.
a box contains 24 transistors, 4 of which are defective if 4 are sold at random . 
find the following probabilities 
a) exactly 2 are not defective 
b) all are not defective 
c) none is defective 
d) almost 1 is defective.


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(a)  P =  {{{(C[4]^2*C[20]^2)/C[24]^4}}} = {{{(((4*3)/2)*((20*19)/2)) /(((24*23*22*21)/(1*2*3*4)))}}} = 0.107284.
              


             
(b)  P =   {{{C[20]^4/C[24]^4}}} = {{{(((20*19*18*17)/(1*2*3*4)))/(((24*23*22*21)/(1*2*3*4)))}}} = 0.455957.
             


(c) is THE SAME as (b)



(d)  MAKES no SENSE.
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