Table of Contents
What is the probability of picking 2 balls of different color?
The probability of getting two red balls is 2C2 / 6C2 = 1/15. The probability of getting two black balls is 3C2 / 6C2 = 3/15. Those scenarios add up to 4/15; every other scenario involves selecting balls of two different colors, so the probability of getting two different colors is 11/15.
How many ways can 5 balls be chosen so that 2 are red and 3 are black?
If you draw five, you HAVE to get at least two black, because there are only three red. There are 3C3 * 5C2 = 10 ways to get three red. Since this is the only way to NOT get three black, there are 56–10 = 46 ways to get at least three black.
How many combinations of 3 balls are there?
The factorial of 3 is 3 * 2 * 1 = 6 . The factorial of 5 is 5 * 4 * 3 * 2 * 1 = 120 , etc. The factorial of 0 is 1. Intuition: Imagine we have to order 3 balls {1, 2, 3}.
How many balls do you need to pick a white ball?
You have 50 white balls and 50 black balls. After you place the balls in the bowls, a random ball will be picked from a random bowl. Distribute the balls (all of them) into the bowls to maximize the chance of picking a white ball.
How many ways can you pick all red balls without replacement?
You are picking 4 balls without replacement. The probability that you pick four red balls is Since you have to pick 4 balls, the number of elements in the sample space would be 11 C 4 (“11 choose 4”). The number of ways of picking all red balls would be 6 C 4. The answer is easly given considering permutations. Indeed the probability is:
What is the probability that you pick four red balls?
The probability that you pick four red balls is Since you have to pick 4 balls, the number of elements in the sample space would be 11 C 4 (“11 choose 4”). The number of ways of picking all red balls would be 6 C 4.
Are black and white balls always odd in numbers?
If you pull out 2 black balls, you replace them with a white ball. On the other hand, if you pull out one black and one white – you replace it with a black ball. So, the black balls would always be odd in numbers – either you remove 2 together or remove 1 and add 1 – so they remain odd always.