4 balls are placed randomly into 10 bins,(adsbygoogle = window.adsbygoogle || []).push({});

what is the probability that exactly 8 of the bins will be empty??

first i need to find out how many ways i can place the balls into the bins --> 10*10*10*10=10000

now i need to find how many ways the balls can be placed so that there are 8 empty bins- or in other words that there are 2 not empty bins

so i choose 2 random bins out of the 10

10C2 = 45

now i need to place the 4 balls

1, 3

2, 2

3, 1

all in all 3 ways

45*3/10000=0.0135,,

the correct answer is 0.63

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Probability of 4 balls in trash can

**Physics Forums | Science Articles, Homework Help, Discussion**