# Multinomial Distribution

• Jan 30th 2009, 10:34 PM
bobbe989
Multinomial Distribution
Hi all,

Need a bit of help with this one. I know I need to use the multinomial distribution, but I'm missing something small;

Question:
If five balanced dice are rolled, what is the probability that the number 1 and the number 4 will appear the same number of times?

The answer should be 2424/6^5. Any ideas on how to get there?
• Jan 31st 2009, 04:01 AM
mr fantastic
Quote:

Originally Posted by bobbe989
Hi all,

Need a bit of help with this one. I know I need to use the multinomial distribution, but I'm missing something small;

Question:
If five balanced dice are rolled, what is the probability that the number 1 and the number 4 will appear the same number of times?

The answer should be 2424/6^5. Any ideas on how to get there?

Calculate Pr(number 1 appears zero times and number 4 appears zero times) + Pr(number 1 appears once and number 4 appears once) + Pr(number 1 appears twice and number 4 appears twice).