Question

Among 7 electrical components exactly one is known not to function properly. If 2 components are randomly selected, find the probability that all selected components function properly.a) 0.2857b) 0.8571c) 0.5714d) 0.6297e) 0.7143f) None of the above

Answer 1

Answer: d

Step-by-step explanation:

Answer 2

Answer:

e) 0.7143

Step-by-step explanation:

Initially, there are 7 components, of which 6 function correctly.

So there is a 6/7 probability that the first component functions properly.

Supposing the first component functions properly, there are now 6 components, of which 5 function properly. So there will be a 5/6 probability that the second component functions properly.

Find the probability that all selected components function properly:

$P = \frac{6]{7}*\frac{5}{6} = \frac{5}{7} = 0.7143$

So the correct answer is:

e) 0.7143