a rectangular game board is composed of identical squares arranged in rectangular array of r rows and r+1 columns.the r rows are numbered from one through r, and the r+1 columns are numbered from 1 through r+1.if r>10 which of the following represents no. of squares on the board that are neither in the fourth row nor in the seventh column?
a]r^2-r
b]r^2-1
c]r^2
d]r^2+1
e]r^2+r