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Need quick help with these perms/coms questionscheck answers

  • #1
rock.freak667
Homework Helper
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[SOLVED] Need quick help with these perms/coms questions..check answers

Homework Statement


A cricket selection committee of 4 members is to be chosen from 5 former batsmen and 3 former bowlers.

In how many ways can this committee be selected so that the committee includes at least

1)One former batsman
2) One batsman and one bowler.


Homework Equations





The Attempt at a Solution



B=Batsman
b=bowlers

1)At least one former batsman

1B 3b=5C1*3C3=5
2B 2b=5C2*3C2=30
3B 1b=5C3*3C1=30
4B 0b=5C4=5

total=70 ways

2) no. of way to select without any restriction=8C4=70

so for at least one B and one b, it is 70-5=65


Also,since in part 1,those are the only ways to make the selection.....does that mean I could have just said 8C4 instead of writing out all the ways?
 

Answers and Replies

  • #2
Dick
Science Advisor
Homework Helper
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618
Yes to all of the above, I think.
 
  • #3
rock.freak667
Homework Helper
6,230
31
well then...great...! I got confused since all of that was 8 marks
 

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