Question 1119070
13 are not defective, so it would be 13/18*12/17, after one non-defective is removed.  Product is 0.5098
1 defective is 
*first one 5/18*13/17
*second one 13/18*5/17; those two products are the same, so multiply by 2, the number of ways, and it is 0.4276.
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both defective is 5/18*4/17=20/304, or 0.0658.  Those three add to 1.0032, which is 1 with rounding error.