There are 11 students (Arash, Omar, Angeline, Rochelle, Joseph,Jennifer, Lindsay
ID: 2953845 • Letter: T
Question
There are 11 students (Arash, Omar, Angeline, Rochelle, Joseph,Jennifer, Lindsay, Artin, Amanda, Kristina and Christopher)1) how many groups of 6 students are there that contain Rochelle,Artin and Kristina?? I got an answer of 20, not sure if itsright...
2) What is the probability of randomly selecting 7 students andgetting Jennifer and Omar in your group? I got an answer of0.38..pretty sure its right but clarification would be nice....
3) There is a class of 20 with 13 boys and 7 girls. A committeewill be formed by randomly selecting 6 people. What is theprobability that the committee will have 3 boys and 3 girls??? Gotan answer of .26 but im not too confident...
YOUR HELP WILL BE MUCH APPRECIATED, THANKS!
Explanation / Answer
There are 11 students (Arash, Omar, Angeline, Rochelle,Joseph, Jennifer, Lindsay, Artin, Amanda, Kristina andChristopher)1) how many groups of 6 students are there that contain Rochelle,Artin and Kristina?? I got an answer of 20, not sure if itsright...
ans= 1*C(8,3)=8!/(5!3!)=8*7*6/(3*2*1)=8*7=56
This is combination problem, order not important
The 1 is the ways to get the three names, of 8 left must choose3.
2) What is the probability of randomly selecting 7 students andgetting Jennifer and Omar in your group? I got an answer of0.38..pretty sure its right but clarification would be nice....
ans =1*C(9,5)/C(11,7)
C(9,5)=9!/(4!5!)=9*8*7*6/(4*3*2*1)=9*2*7=126
C(11,7)=11!/(7!*4!)=11*10*9*8*/(4*3*2*1)=330
ans= 126/330=.38
3) There is a class of 20 with 13 boys and 7 girls. A committeewill be formed by randomly selecting 6 people. What is theprobability that the committee will have 3 boys and 3 girls??? Gotan answer of .26 but im not too confident...
ans=C(13,3)C(7,3)/C(20,6)=10010/38760=.258
...
I hope this helps
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