-->

Probability

Question
CBSEENMA12033854

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

Solution

Here n = 8
                  straight p space equals space 5 over 100 space equals 1 over 20 comma space space space straight q space equals space 1 space minus space straight p space equals space 1 minus 1 over 20 space equals space 19 over 20
P(less than 2 defective item) = P(0) + P(1)
                             equals space straight C presuperscript 8 subscript 0 space open parentheses 19 over 20 close parentheses to the power of 8 space plus space space straight C presuperscript 8 subscript 1 space open parentheses 19 over 20 close parentheses to the power of 7 space open parentheses 1 over 20 close parentheses
space equals space open parentheses 19 over 20 close parentheses to the power of 7 space space open square brackets 1 cross times 19 over 20 plus 8 over 20 close square brackets space equals space open parentheses 19 over 20 close parentheses to the power of 7 space cross times 27 over 20

Some More Questions From Probability Chapter