Let x be the original no. of rows & y be the original no. of student s in each row.

Total no. of students = xy.

Acc. to problem

(y + 1) (x - 2) = x y ....(i)

and (y - 1) (x + 3) = xy ....(ii) Solving (i) & (ii) to get

x = 12 & y = 5

Total no. of students = 60