Statistics And Probability Question 477

Question: The items produced by a firm are supposed to contain 5% defective items. The probability that a sample of 8 items will contain less than 2 defective items, is

[MP PET 1993]

Options:

A) $ \frac{27}{20},{{( \frac{19}{20} )}^{7}} $

B) $ \frac{533}{400},{{( \frac{19}{20} )}^{6}} $

C) $ \frac{153}{20},{{( \frac{1}{20} )}^{7}} $

D) $ \frac{35}{16},{{( \frac{1}{20} )}^{6}} $

Show Answer

Answer:

Correct Answer: A

Solution:

  •         Required probability                  $ ={}^{8}C_1{{( \frac{1}{20} )}^{1}}{{( \frac{19}{20} )}^{7}}+{}^{8}C_0{{( \frac{1}{20} )}^{0}}{{( \frac{19}{20} )}^{8}}=\frac{27}{20}{{( \frac{19}{20} )}^{7}} $