What will you be doing over the Easter break? >>

What will you be doing over the Easter break? >>

What will you be doing over the Easter break? >>

Combinations and permutations question

heres the question:

Three married couples, Mr & Mrs Lee, Mr & Mrs Martin, and Mr & Mrs Shah, stand in a line for a photograph to be taken. Find the number of different ways in which these six people can be arranged if no man stands next to another man.

Whenever I try this question I get 72 (3! x 3! x 2!) as the answer but apparantly the answer should be 144. Can anyone tell me where I'm going wrong?

Thanks.

the possibliities are
M W M W M W = 3! * 3!
W M W M W M = 3! * 3!
M W W M W M = 3! * 3!
M W M W W M = 3! * 3!
total = 144

OP

Retropmot

no
the possibliities are
M W M W M W = 3! * 3!
W M W M W M = 3! * 3!
M W W M W M = 3! * 3!
M W M W W M = 3! * 3!
total = 144

Oh yes - thanks I forgot about the second two possibilities!

Latest

Trending

Articles for you

Top questions to ask at a university open day - and how to be well prepared

Top questions to ask at a university open day - and how to be well prepared

First and insurance university choices explained

First and insurance university choices explained

I want to go to uni but I don't know what to study

I want to go to uni but I don't know what to study

Six things you need to know before making your final A-level choices

Six things you need to know before making your final A-level choices

Try out the app

Continue on web