Dont be consecutive
20 persons are in a row and John wants to pick 7 out of them.In how many ways can John select them such that at least one person finds the person next to him (in the row) is also selected. If K is the number of ways, give your answer as greatest integer less than
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
No. of ways = total no. of ways of selecting 7 people - (No. of ways in which no two people are consecutive) = ( r n ) - ( r n − r + 1 ) ; K = ( 7 2 0 ) - ( 7 1 4 ) ; 1 0 4 K = 7.4088