SOLUTION: There are 7 boys and 3 girls. If we randomly select 5 kids what is the probability that all 3 girls will be picked? What is the probablilty that none of the girls will be picked

Click here to see ALL problems on Probability-and-statistics

Question 356433: There are 7 boys and 3 girls. If we randomly select 5 kids
what is the probability that all 3 girls will be picked?
What is the probablilty that none of the girls will be picked?
What is the probability of 2 girls getting picked
Found 2 solutions by edjones, stanbon:
Answer by edjones(8007) (Show Source):
You can put this solution on YOUR website!
7 boys and 3 girls
nCr=combination of n things taken r at a time.
a)
(3C3 * 7C2)/10C5
=1*21/252
=1/12 probability that all 3 girls will be picked.
.
b)
7C5/10C5
=21/252
=1/12 probablilty that none of the girls will be picked.
.
c)
(3C2 * 7C3)/10C5
=3*35/252
=105/252
=5/12 probability of 2 girls getting picked.
.
Ed

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
There are 7 boys and 3 girls. If we randomly select 5 kids
---
Binomial problems with n = 5, p(boy) = 0.7, and P(girl) = 0.3
--------------------
what is the probability that all 3 girls will be picked?
# of ways to pick 3 girls and 2 boys = 1*7C2 = 21
# of ways to pick 5 kids randomly: 10C5 = 252
P(3 g and 2 b's) = 21/252 = 0.08333
--------------------------------------------
What is the probability that none of the girls will be picked?
P(o g and 5 b's) = 7C5/10C5 = 0.083333
---------------------------
What is the probability of 2 girls getting picked
P(2 g's and 3 b's) = 3C2(0.3)^2(0.7)^3 = 0.0926
================================================
Cheers,
Stan H.