**Quote:**

In a certain room each row of chairs has the same number of chairs, and the no. of rows is one less than the no. of chairs in a row. How many chairs are in a row?

1) There is a total of 72 chairs

2) After 1 chair is removed from the last row, there is a total of 17 chairs in the last two rows.

My approach:

1) If there are "n" chairs in a row, there will be "n-1" rows .

So total no. of chairs in the room would be = n(n-1)

Hence, n(n-1)=72, thus, Sufficient.

2) I cldnt really work on this.

In a certain room each row of chairs has the same number of chairs, and the no. of rows is one less than the no. of chairs in a row. How many chairs are in a row?

1) There is a total of 72 chairs

2) After 1 chair is removed from the last row, there is a total of 17 chairs in the last two rows.

My approach:

1) If there are "n" chairs in a row, there will be "n-1" rows .

So total no. of chairs in the room would be = n(n-1)

Hence, n(n-1)=72, thus, Sufficient.

2) I cldnt really work on this.

Posted: Sun Jul 12, 2009 12:51 pm

Thats the exact approach i took x(x+1)= 72 so x is 8 or -9, it cant be negative so A is enuf..and as you said B is enuf.. so answer is 'D'

are you in doubt ? or you want to share your method ?