# math

posted by .

we have box,in box 3 white balls,4 red balls,4 black balls..how i choose 2 black balls and 3 red balls successively?

• math -

chance of picking 1 black first = 4/11

now have 3 w , 4 r , 3 b or 10
chance of picking black second = 3/10

now have 3 w ,4 r, 2 b or 9
chance of picking red = 4/9

now have 3 w, 3 r , 2 b or 8
chance of picking red = 3/8

now have 3 w , 2 r , 2 b or 7
chance of picking res = 2/7
so

4/11 * 3/10 * 4/9 * 3/8 * 2/7

## Similar Questions

1. ### Math

my problem is: From the box containing 5 red balls, 7 blue balls, 10 black balls. you select 4 balls what is the probabilty that EXACTLY 2 balls are black. so i know how to start it c(10,2)c(2,1) ---------- c(22,40 but how do you solve …
2. ### Math

my problem is: From the box containing 5 red balls, 7 blue balls, 10 black balls. you select 4 balls what is the probabilty that EXACTLY 2 balls are black. i know that you start it/set it up like this: c(10,2)c(2,1) divided by c(22,4) …
3. ### statistics

A box contains 3 white and 5 black balls. Four balls are drawn at random "with replacement" from the box (i.e. selected balls are returned to the box and mixed, before drawing the next ball). Let X be the number of black balls drawn. …
4. ### maths-probabilty

A box contains 5 red balls and 6 black balls. in how many ways can 6 balls be selected so that there are at least two balls of each color?
5. ### maths-probabilty(urgently needed)

A box contains 5 red balls and 6 black balls. in how many ways can 6 balls be selected so that there are at least two balls of each color?
6. ### Math

A bag contains three black balls, four white balls and five red balls. Three balls are removed without replacement. What is the probability of obtaining a one of each colour b at least two red balls ?
7. ### pshs

three balls are drawn successively from a box containing 6 red balls,4white balls and 5 blue balls. find the probability that tare hey drawn in the order red,white and blue if each ball is replaced?
8. ### Math

A box contains 8 white balls, 7 black and 4 red. How many red balls must be added to the box so that the probability is 3/4?
9. ### maths

a box contains 5 red balls and 6 black balls in how many ways can 6 balls be selected so that there are atleast two balls of the same colour
10. ### math

In a box contain 4 green balls 4 white balls and 4 red balls .If 4 balls are drown randomly what is the probability that no one even out of the 4 balls being white.

More Similar Questions