Question

There are 5 boys and 4 girls in my class.

In how many ways can they be seated in a row of 9 chairs such that at least 3 girls are all next to each other?

Answer 1

have you learned factorials or the use of the exclamation mark ?

Answer 2

yes factorials

Answer 3

i'm not really sure about this, but I think this is how it works
having 3 girls together, 5 boys and 1 girl alone.
3! x 6 x 5! x 5 = 21600
having 4 girls together and 5 boys
4! x 6 x 5! = 17280
add them
21600 + 17280 = 38880 possibilities

Answer 4

its not right i was thinking of 36120 possibilites

Answer 5

mmm I'm not getting that number... let me think again

Answer 6

me too

Answer 7

case I ; 3 girls..

3! * 7 !

case 2; 4 girls..

4! * 6!...

Try this..