- #1

desmond iking

- 284

- 2

## Homework Statement

Two items are chosen at random from a batch of items containing 90 good and 2 defective ones.

find the probability of at least one out of two items is defective

## Homework Equations

## The Attempt at a Solution

P(defective , good) +P(good , defective) + P(defective , defective) =

((10/100) x (90/99)) + ((90/100) x (10/99)) + ((10/100) x (9/99))= 0.1909 (correct ans)

why can't i do on this way?

P( 1 defective , i good ) +P (2 defective) = ((2c1 x 90c1)/(92c2)) + (2c2/92c2)= 0.0452