SOLUTION: A ball is drawn at random from a box containing 10 red balls, 30 white balls, 20 blue balls and 15 black balls. Obtain the probability that the ball drawn is a) black or red b)

Question 1157521: A ball is drawn at random from a box containing 10 red balls, 30
white balls, 20 blue balls and 15 black balls. Obtain the probability
that the ball drawn is
a) black or red
b) not red or blue
c) not blue
d) white
e) red, white or blue
Answer by Edwin McCravy(20065) (Show Source): You can put this solution on YOUR website!
A ball is drawn at random from a box containing 10 red balls, 30
white balls, 20 blue balls and 15 black balls.

There are 10 reds +30 whites + 20 blues + 15 blacks = 75 balls in the box.

a) Obtain the probability
that the ball drawn is black or red

15 blacks + 10 reds
------------------- = 25/75 = 1/3
     75 balls

b) Obtain the probability
that the ball drawn is not red or blue

30 whites + 15 blacks 
--------------------- = 45/75 = 3/5
      75 balls

c) Obtain the probability
that the ball drawn is not blue

10 reds + 30 whites + 15 blacks
------------------------------- = 55/75 = 11/15
          75 balls

d) Obtain the probability
that the ball drawn is white

  30 whites 
------------------- = 2/5 
  75 balls

e) Obtain the probability
that the ball drawn is red, white or blue

 
10 reds + 30 whites + 20 blues
------------------------------- = 60/75 = 4/5
          75 balls

Edwin

RELATED QUESTIONS
two balls are drawn at random without replacement from a box containing 6 red balls, 4... (answered by ewatrrr)

A ball drawn at random from a box containing 6 red balls, 4 white balls, and 5 blue... (answered by rothauserc)

A ball is drawn at random from a box containing 7 red balls, 4 white balls and 6 yellow... (answered by DrBeeee)

there are 3 boxes containing respectively 1 white, 2 red, 3 black balls; 2 white, 3 red,... (answered by Theo,ikleyn)

a box contains 6 red,4 white and 5 black balls .A person draws 4 balls from the box at... (answered by stanbon)

A box contains 6 red, 4 white and 5 black balls. A person draws 4 balls from the box at... (answered by stanbon)

A box contains 6 red, 4 white and 5 black balls. A man draws 4 balls from the box at... (answered by math_helper,Edwin McCravy)

A box contains 20 balls out which 7 are white balls, 5 are black balls, 6 are red balls... (answered by Boreal)

Three boxes containing red, white and blue balls are used in an experiment. Box 1... (answered by CPhill)