Question

Usually, errors are found in 10% of lines of code written by software engineers at Error Free Code, Inc. What is the probability that in a randomly selected sample of 5 lines of code 2 of them have errors?

Answer 1

Answer: The required probability is 0.008.

Explanation:

Since we have given that

Probability of getting codes having no error = 10% = q

Probability of getting codes having error = 100-10=90%.= q

So, sample n = 5

X = 2 (i.e. code 2 of them have errors)

Using "Binomial theorem":

`P(X=n)^nC_xp^xq^(n-x)`

`P(X=2)=^5C_2(0.9)^2(0.10)^3=0.008`

Hence, the required probability is 0.008.