Sunday, November 15, 2009

Probability. flower seeds! help me please! =)?

two flower seeds are randomly selected from a package that contains 5 seeds for red flowers, and 3 seeds for white flowers.


a) what is the probability that both seeds will result in red flowers?


b) what is the probability both colors are represented?


c) what is the probability both seeds are white flowers?

Probability. flower seeds! help me please! =)?
Since there are 8 seeds in the package,


there are (8)(7)/2=28 possible two seed combinations.


This is because there are 8 seeds for the first choice, times 7 seeds for the second choice, divided by 2, since there are two different orders that you can select each pair of seeds.


Of those 28 combinations, (5)(4)/2=10 combinations will both be red,


(3)(2)/2=3 will both be white, and


(5)(3)=15 combinations including both colors.


To answer your question,


a) p=10/28


b) p=3/28


c) p=15/28


Notice that when I figured the probability that both colors would be represented, I paired the 5 red seeds with the 3 white seeds to yield 15 combinations.


When figuring the combinations of just white seeds, and just red seeds, I divided by two to keep from counting each pair of seeds twice.
Reply:assume without replacement.





there are 8 seeds total.





a) the probabity of picking a seed that is for red flowers is 5/8. After one seed is picked out, there are 7 seeds left and 4 out of which are seeds for red flowers. That gives you the probability of picking a second seed that is also for red flower is 4/7





P = (5/8) * (4/7)


P = 5/14





b) both colors are presented. One for red flowers and one for white flowers





for red flower: P = 5/8





one seed is picked out, 7 are left. and 3 of them are for white flower





since order does not matter, there are two ways you can pick the two seeds


Red and white


white and red





P = 2 (5/8) (3/7)


P = 15/28 %26lt;== answer





c) same concept


P = (3/8) (2/7)


P = 3/28 %26lt;== answer
Reply:5/8 times 4/7= 20/56= 5/14


5/8 times 3/7= 15/56+15/56=30/56=15/28


3/8 times 2/7= 6/56= 3/28
Reply:a) ( 5/8 x 4/7 ) = 5/14


b) ( 5/8 x 4/7 ) + ( 3/8 x 2/7 ) = 0.03827


c) (3/8 x 2/7) = 3/28


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