Men and women
There are 8 women and 5 men.
If the number of ways I can arrange them in a row such that no men are next to each other can be written as a ! × ( r n ) . Find n+a+r. Assume ( r n ) = ( n − r ) ! n ! .
The answer is 22.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
The answer is correct till
8 ! ∗ ( 9 P 5 )
This equals 8 ! ∗ 9 ! / 4 !
I can rearrange this as
9 ! ∗ ( 8 P 4 )
Which will give different answer.
Although the ques is framed to test basic approach of solving this problem..but someone can always think out of the box!
Hey, dude you really got me!!
You asked what is n+a+p.
I know what is n, what is a but what the hell is p.
At first, I thought it's the number of permutations, thus i entered 9+8+121927680
= 1 2 1 9 2 7 6 8 0
As soon as I pressed submit, the red light came flashing it's wrong!
Then, i typed 9+8+5
= 2 2
Then, it showed that it was correct and then only I heaved a sigh of relief!
It will be better if you change p with r.
Log in to reply
Ahh yes, fixed it. Thank you for that.
Log in to reply
i see this problem just 3 DAYS ago in a competition lol
In this simple diagram. O represents a woman's space and M represents where a man or no one is.
MOMOMOMOMOMOMOMOM
We need to know how many ways we can arrange 8 women into 8 slots. Thus we have 8!
Now, we have 5 men and 9 slots, thus 4 will be empty. So we need How many ways we can pick 5 out of 9 slots. Thus we have 9 P 5 .
Since there are 8! Ways we can arrange the women with one arrangement of men, we must multiply them and are left with 8 ! ∗ ( 9 P 5 ) .
So our answer is 8 + 9 + 5 = 2 2