SOLUTION: Probability Question: If a factory worker places 103 created circuits on a shelf to be checked for quality, of course, 11 won't work. She is then asked to randomly select two cir

Question 249324: Probability Question: If a factory worker places 103 created circuits on a shelf to be checked for quality, of course, 11 won't work. She is then asked to randomly select two circuits, without replacement, from the shelf. What is the chance that both circuits she selects will be defective?
Answer by edjones(8007) (Show Source): You can put this solution on YOUR website!
nCr = n!/((n-r)!r!) Combination of n things taken r at a time.
.
11C2 Combinations of 11 bad circuits taken 2 at a time. = 55
103C2 Combinations of all circuits taken 2 at a time. = 5253
.
55/5253=.0105 chance both are defective.
.
Ed
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