[MOVED] Please Help: You have a bag of 400 marbles....

[keys360]

I'll pose my problem as a question.

You have a bag of 400 marbles. 16 red marbles and 384 blue marbles. If you were to randomly draw only 4 marbles from the bag, what would be the odds of pulling out 4 red marbles in a row?

Please please please help a dummy out!!!

 

[galactus]

Your odds of picking a red marble out of the sack is 16/400=1/25.

The odds of drawing a second red are 15/399=5/133.

The odds of drawing a third is 14/398=7/199.

The odds of drawing the fourth is 13/397.

\(\displaystyle (\frac{1}{25})(\frac{5}{133})(\frac{7}{199})(\frac{13}{397})=\frac{13}{7505285}\approx{.000001732}\).

 

[keys360]

Thanks for the response!