There are 5 girls and 6 boys. Find the number of arrangement if they are to be arranged in 2 rows,(1st row: 5 seats, 2nd row: 6 seats). The boys and girls must stand alternately.
@oldrin.bataku
You can youe the concept of Matrices
Doy you know how ?
no
But, wait you can solve it using combination
Umm maybe the use of permutation and combination?
yes
Is it 5C2 x 6C3 x (1st row):6.5.5.4.4 x (2nd row):3.3.2.2.1.1=17280000
Stand alternately?
boy girl boy girl
There are 5 girls and 6 boys. Find the number of arrangement if they are to be arranged in 2 rows,(1st row: 5 seats, 2nd row: 6 seats). The boys and girls must stand alternately. There are \(5!\) ways to order the girls and you have \(2\) ways to seat them. For a particular seating of the girls, you end up with \(6!\) ways to order the boys in the remaining seats. I found \(5!\times6!\times2=172800\)
oops! there is actually only 1 way to seat them: B G B G B G B G B G B 6 * 5 * 5 * 4 * 4 * 3 * 3 * 2 * 2 * 1 * 1 so forget the 2, only \(5!\times6!=86400\)
What about this, 1st row- B G B G B 6. 5. 5.4.4 2nd row- we can either start with a boy or a girl, B G B G B G 3.3.2.2.1.1 so we multiply by 2 =172800
@nick96 you can't start with either boy or girl though
If you start with girls, observe: G B G B G B G B G B B
But IF the question states that boy and girl stand alternately in a row ,then 172800 is correct right?
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