A rectangular game board is composed of identical squares arranged in a rectangular array of r rows and r+1 columns. The r rows are numbered from 1 through r, and the r+1 columns are numbered from 1 through r+1. If r10, which of the following represents the number of squares on the board that are neither in the 4th row nor in the 7th column?

A. r^2 - r
B. r^2 - 1
C. r^2
D. r^2 + 1
E. r^2 + r

Question

A rectangular game board is composed of identical squares arranged in a rectangular array of r rows and r+1 columns. The r rows are numbered from 1 through r, and the r+1 columns are numbered from 1 through r+1. If r>10, which of the following represents the number of squares on the board that are neither in the 4th row nor in the 7th column?

A. r^2 - r
B. r^2 - 1
C. r^2
D. r^2 + 1
E. r^2 + r

anonymous · Answer

just remove one row and one column....the ans will be same if u remove any row or column... so the remaining will be r-1 rows and r columns so there will be r(r-1) squares...which is a. r^2-r