Question

Find the probability

A bag contains five red balls and four white balls, if three
balls are removed from the bag, that:

a) they are all red;

b) two are red, one white;

c) they are all white;

d) two are white, one red;

I try to use nCr/nPr but seems getting the different answer to the solution, eg in a). if I use nCr (n=5, r =3) I got 10 which is correct, however for nPr (n = 9, r = 3) i didn't get 84. instead I got 504. the solution I have been given is nCr = 5 / nPr = 42.

Answer #1

This is sampling without replacement (order not important - Hence use combination nCr not nPr)

The bag contains five red balls and four white balls. 3 balls are removed from the bag. The number of ways of choosing 3 balls from 5+4=9 balls is .

a) The probability that they are all red is

b) The probability that two are red, one white is

c) The probability that they are all white is

d) The probability that two are white, one red

A bag contains red balls and white balls. If five balls
are to be pulled from the bag, with replacement, the probability of
getting exactly three red balls is 32 times the probability of
getting exactly one red ball. What percent of the balls originally
in the bag are red?

Q9. A bag contains 4 white, 5 red and 6 blue balls. Three
balls are drawn at random from the bag. What is the probability
that at least 2 are red.

A bag contains 5 white and 8 red balls. Two drawing of 3 balls
are made such that i) balls are replaced before the second trial.
ii) balls are not replaced before the second trial. Find the
probability that the first drawing will be 3 white and second
drawing will be 3 read in each case.

Two balls are drawn from a bag containing 5 white balls and 7
red balls. If the first ball is replaced before the second is
drawn, what is the probability that the following will occur?
(Enter your probabilities as fractions.)
(a) both balls are red
(b) both balls are white
(c) the first ball is red and the second is white
(d) one of the balls is black

A bag contains 7 red balls and 5 white balls. Two balls are
drawn without replacement. (Enter your probabilities as
fractions.)
(a) What is the probability that the second ball is white, given
that the first ball is red?
(b) What is the probability that the second ball is red, given that
the first ball is white?
(c) Answer part (a) if the first ball is replaced before the second
is drawn.

There are 10 balls in a bag. 3 are red, 5 are white, 2 are blue.
You are to randomly choose two balls, taking one out and then
another without replacement.
What is the probability that you will get two red balls?

A bag contains 6 red balls and 7 white balls. Two balls are
drawn without replacement. (Enter your probabilities as
fractions.)
(a) What is the probability that the second ball is white, given
that the first ball is red?
(b) What is the probability that the second ball is red, given
that the first ball is white?
(c) Answer part (a) if the first ball is replaced before the
second is drawn.

There are 10 balls in a bag. 3 are red, 5 are white, 2 are blue.
You are to randomly choose two balls, taking one out and then
another with replacement.
What is the probability you will get two blue balls?

There are five red balls and three white balls in a box. An
experiment consist of drawing three balls in succession. Once a
ball is drawn, it is not replaced. a. What is the probability that
two or more red balls will be obtained in the three draws? b. What
is the probability that exactly two white balls and one red ball
will be obtained in the three draws? c. Given a white ball is
selected on the first draw,...

Two balls are drawn from a bag containing 4 white balls and 3
red balls. If the first ball is replaced before the second is
drawn, what is the probability that the following will occur?
(Enter your probabilities as fractions.)
(a) both balls are red
(b) both balls are white
(c) the first ball is red and the second is white
(d) one of the balls is black
A die is thrown twice. What is the probability that a 2...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 15 minutes ago

asked 18 minutes ago

asked 29 minutes ago

asked 44 minutes ago

asked 52 minutes ago

asked 57 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago