ccheryn
suddenly a strange doubt,
I completely agree upon the above method,
can we solve the same problem by considering as follows,
probablility of one male to be selectedis 1/8,
prbablity of two female to be seleced 2/7
so probalility is 1/8 * 2/7
or 2 male and 1 female = 2/8 * 1/7
addin both gives 4/8*7 = 1/14. i know somewhere i am wrong...
but i want to arrive at the answer in this approach.
can somebody help?
Hi Cheryn,
Overall we have 15 plants, 8 male and 7 female. So:
1. Probability of choosing 1 female out of 15 is 7/15
2. Probability of choosing 1 male out of 15 is 8/15
As you wrote, we can have two different sets of three plants: either Male+Male+Female or Female+Female+Male
Let’s first choose 2 males and 1 female: 8/15 – first male
7/14 – second male, out of remaining 14 plants
7/13 – first female, out of remaining 13 plants
3 – ways of arranging the set: MMF, MFM, and FMM
So the probability of choosing Male+Male+Female is 8/15*7/14*7/13*3 = 28/65
Now we chose 2 females and 1 male:7/15 – first female
6/14 – second female, out of remaining 14 plants
8/13 – first male out of remaining 13 plants
3 – ways of arranging the set: FFM, FMF, and MFF
So the probability of choosing Female+Female+Male is 7/15*6/14*8/13*3 = 24/65
Total: Male+Male+Female + Female+Female+Male = 28/65 + 24/65 = 4/5
Learning this method is helpful to understand the Probability concept in greater detail. However, using combinatorics is much less cumbersome.