quick permutations question (1 Viewer)

[ianc]

hi all

I have done a question, but haven't got the solution, so was wondering could someone give me an answer?

There are 8 candidates to take an exam, 3 in Maths and 5 in English. In how many ways can they be seated in a row if the 3 Maths candidates cannot sit together?

Thanks!

 

[pLuvia]

Ways of the maths candidates sitting together=6!x3!
Ways of the maths candidates not sitting together=8!-(6!x3!)=36000

Edit: Mistake, thanks Riviet

 

[Riviet]

pLuvia - you forgot that the 3 maths guys can be rearranged in 3! ways.

.'. no. of ways = 8! - (6! x 3!)

 

[Shady01]

Can two of them sit together though?

 

[pLuvia]

Can two of them sit together though?

Nope, unless the question states that

 

[haque]

if dealing with the case where all three are separated then the above two answers are wrong, however the way the question is stated it would imply that 2 people would be allowed together.?

 

[Riviet]

if dealing with the case where all three are separated then the above two answers are wrong, however the way the question is stated it would imply that 2 people would be allowed together.?

Hmm good point, I think we would assume that 2 of them adjacent would be counted. If not, then I guess we would subtract those arrangements.

 

[haque]

based on the way its worded ur answer should be right riviet