SOLUTION: Rework problem 28 from section 3.4 of your text, involving the drawing of two balls from a box of colored balls. Assume the box contains 10 balls: 5 red, 3 blue, and 2 yellow. A ba

Algebra.Com
Question 1135130: Rework problem 28 from section 3.4 of your text, involving the drawing of two balls from a box of colored balls. Assume the box contains 10 balls: 5 red, 3 blue, and 2 yellow. A ball is drawn and its color noted. If the ball is yellow, it is replaced; otherwise, it is not. A second ball is then drawn and its color is noted.
What is the probability that the first ball was yellow, given that the second was red?

Answer by Boreal(15235)   (Show Source): You can put this solution on YOUR website!
One can make a tree diagram and determine that
RR is 2/9
RB is 1.5/9
RY is 1/9
BR is 1.5/9
BB is .6/9
BY is .6/9
YR is 1/10
YB is 6/100
YY is 4/100
Those do add to 1.00
So, if the second is red 10/100+15/90+20/90 or 35/90 + 10/100 or 440/900,
the first one was yellow is 10/100 or 90/900
The answer is 90/440 or 0.2045

RELATED QUESTIONS

Rework problem 15 from section 3.5 of your text involving a true-false test. Assume that... (answered by edjones)
A box contains 4 white balls and 3 red balls. Three balls are drawn from the box without (answered by Boreal)
Two balls are drawn without replacement from a box containing 4 red and 3 yellow balls.... (answered by Fombitz)
A Barrel contains 12 yellow balls and 10 red balls. You are drawing 7 balls from the... (answered by ewatrrr)
two balls are drawn at random without replacement from a box containing 6 red balls, 4... (answered by ewatrrr)
A box contains 2 white balls, 3 black balls and 4 red balls. What is the probability of... (answered by Alan3354)
A box contains 5 red,3 green and 4 blue balls of the same size.if a boy picks two balls... (answered by Fombitz)
Rework problem 17 from section 3.2 of your text, involving the sum of the numbers... (answered by edjones)
Three boxes containing red, white and blue balls are used in an experiment. Box 1... (answered by CPhill)