viernes, 8 de febrero de 2013

Information theory and coding methods - EXTRA POINTS

Good day, to this entry we were given the freedom to choose a problem of any exercise of chapter 1 of this book.

My problem is a follows:


Exercises 1.3
1. An urn contains six red balls, five green balls, and three yellow balls. Two are drawn without replacement. What is the probability that at least one is yellow?

Traducción:
1. Una urna contiene seis bolas rojas, cinco bolas verdes, y tres bolas amarillas. Dos se extrae sin reemplazo. ¿Cuál es la probabilidad de que al menos uno es de color amarillo?

Solution

We make clear that at least one ball is yellow, so...we have many "answers":

  •  green-YELLOW
  •  red-YELLOW
  •  YELLOW-YELLOW
  •  YELLOW-red
  •  YELLOW-green

Make a drawing to explain better...




so, the probability of getting at least one yellow ball is 30%