A manufacturer is using glass as the surface for the multi-touch screen of its smartphone. The glass on the manufactured phone has a 5% probability of not passing quality control tests. The quality control manager bundles the smartphone in groups of 10. If that bundle has any smartphone that does not pass the quality control test, the entire bundle of 10 is rejected.

What is the probability that a smartphone bundle that will be rejected by quality control?

(A) 0.25

(B) .05^10

(C) 1-0.95^10

(D) 1-0.05^10

(E) 0.95^10

could you please explain why the power is raised to 10. is it because 10 phone so raise by 10 or any other explanation?

probability for one phone passing the test = 0.95
probability for 10 phones passing the test = 0.95 AND 0.95 AND 0.95 ..... = 0.95 * 0.95 * 0.95 .... = 0.95^10
probability for at least one phone not passing the test = 1 - 0.95^10

Answer: C

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________